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Washington, Jun 1: Police fired tear gas outside the White House late Sunday as major US cities were put under curfew to suppress rioting as anti-racism protestors again took to the streets to voice fury at police brutality.

With the Trump administration branding instigators of six nights of rioting as domestic terrorists, there were more confrontations between protestors and police and fresh outbreaks of looting.

Violent clashes erupted repeatedly in a small park next to the White House, with authorities using tear gas, pepper spray and flash bang grenades to disperse crowds who lit several large fires and damaged property.

Local US leaders appealed to citizens to give constructive outlet to their rage over the death of an unarmed black man in Minneapolis, while night-time curfews were imposed in cities including Washington, Los Angeles and Houston.

One closely watched protest was outside the state capitol in Minneapolis' twin city of St. Paul, where several thousand people gathered before marching down a highway.

"We have black sons, black brothers, black friends, we don't want them to die. We are tired of this happening, this generation is not having it, we are tired of oppression," said Muna Abdi, a 31-year-old black woman who joined the protest.

"I want to make sure he stays alive," she added in reference to her son, aged three.

Hundreds of police and National Guard troops were deployed ahead of the protest.

At one point, some of the protestors who had reached a bridge were forced to scramble for cover when a truck drove at speed after having apparently breached a barricade.

The driver was later taken to hospital after the protestors hauled him from the vehicle, although there were no immediate reports of other casualties.

There were other large-scale protests in cities including New York and Miami.

Washington's mayor ordered a curfew from 11:00 pm until 6:00 am, as a report in the New York Times said that President Donald Trump had been rushed by Secret Service agents into an underground bunker at the White House on Friday night during an earlier protest.

Stores ransacked

Large-scale violence has rocked many US cities in recent days, and looters ransacked stores in a neighborhood of Philadelphia on Sunday.

In the Los Angeles suburb of Santa Monica, looting was reported at stores in a popular beachside shopping center.

Officials in LA -- a city scarred by the 1992 riots over the police beating of Rodney King, an African-American man -- imposed a curfew from 4:00 pm Sunday until dawn.

"Please, use your discretion and go early, go home, stay home and help us make sure that those who want to change this conversation from being about racial justice to be about burning things and looting things, don't win the day," the city's mayor Eric Garcetti said on CNN.

The shocking videotaped death last Monday of an unarmed black man, George Floyd, at the hands of police in Minneapolis ignited the nationwide wave of outrage over law enforcement's repeated use of lethal force against unarmed African Americans.

Floyd stopped breathing after Minneapolis police officer Derek Chauvin knelt on his neck for nearly nine minutes.

Chauvin has been charged with third-degree murder and is due to make his first appearance in court on Monday. Three other officers with him have been fired but for now face no charges.

Governor Tim Walz has mobilized all of Minnesota's National Guard troops  -- the state guard's biggest mobilization ever -- to help restore order.

Police fired tear gas and stun grenades to clear streets of curfew violators Saturday night in Minneapolis.

Walz extended a curfew for a third night Sunday and praised police and guardsmen for holding down violence. "They did so in a professional manner. They did so without a single loss of life and minimal property damage," he said.

"Congratulations to our National Guard for the great job they did immediately upon arriving in Minneapolis, Minnesota, last night," President Donald Trump tweeted, adding that they "should be used in other States before it is too late!"

The Department of Defense said that around 5,000 National Guard troops had been mobilized in 15 states as well as the capital Washington, with another 2,000 on standby.

The widespread resort to uniformed National Guards units is rare, and it evoked disturbing memories of the rioting in US cities in 1967 and 1968 in a turbulent time of protest over racial and economic disparities.

Trump blamed the extreme left for the violence, saying he planned to designate a group known as Antifa as a terrorist organization.

"The violence instigated and carried out by Antifa and other similar groups in connection with the rioting is domestic terrorism and will be treated accordingly," added Attorney General Bill Barr.

'A nation in pain'

Atlanta Mayor Keisha Lance Bottoms said Trump, who has often urged police to use tough tactics, was not helping matters.

"We are beyond a tipping point in this country, and his rhetoric only enflames that," she said on CBS.

Joe Biden, Trump's likely Democratic opponent in November's presidential election, visited the scene of one anti-racism protest.

"We are a nation in pain right now, but we must not allow this pain to destroy us," Biden tweeted, posting a picture of him speaking with an African-American family at the site where protesters had gathered in Delaware late Saturday.

Floyd's death has triggered protests beyond the United States, with hundreds rallying outside the US embassy in London in solidarity.

"I'm here because I'm tired, I'm fed up with it. When does this stop?" Doreen Pierre told AFP at the protest.

In Germany, England football international Jadon Sancho marked one of his three goals for Borussia Dortmund against Paderborn by lifting his jersey to reveal a T-shirt bearing the words "Justice for George Floyd".

Beijing, Jan 23: China is putting on lockdown a city of 11 million people considered the epicenter of the new coronavirus outbreak that has killed 17 and infected nearly 600 people, as health authorities around the world work to prevent a global pandemic.

The previously unknown coronavirus strain is believed to have emerged late last year from illegally traded wildlife at an animal market in the central Chinese city of Wuhan. Cases have been detected as far away as the United States, stoking fears the virus is already spreading worldwide.

Wuhan's local government said it would shut down all urban transport networks and suspend outgoing flights from the city as of 10 a.m. (0200 GMT) Thursday, state media reported, adding that the government is urging citizens to not leave the city in the absence of special circumstances.

Contrasting with its secrecy over the 2002-03 Severe Acute Respiratory Syndrome (SARS), which killed nearly 800 people, China's communist government has this time given regular updates to try to avoid panic as millions of people travel for the Chinese Lunar New Year holiday.

Chinese authorities have confirmed 571 cases and 17 deaths as of end-Wednesday, state television reported on Thursday. There are eight other known cases around the world - Thailand has confirmed four cases, while the United States, Taiwan, South Korea and Japan have each reported one.

Vice Premier Sun Chunlan said during a visit to Wuhan that authorities needed to be open about the spread of the virus and their efforts to contain it, the official Xinhua news agency reported on Thursday, comments likely to reassure global health experts.

After a meeting at its Geneva headquarters on Wednesday, the World Health Organization (WHO) said it would decide on Thursday whether to declare the outbreak a global health emergency, which would step up the international response.

If it does so, it will be the sixth international public health emergency to be declared in the last decade.

WHO Director-General Tedros Adhanom Ghebreyesus told reporters in Geneva that China's actions so far were "very strong" but called in Beijing to take "more and significant measures to limit or minimise the international spread".

"We stressed to them that by having a strong action not only they will control the outbreak in their country but they will also minimise the chances of this outbreak spreading internationally. So they recognise that," he said.

A senior U.S. State Department official also called on China to "play a bigger role in global health so they taking more and significant measures to limit or minimise the international spread".

"The lack of transparency in the past, especially with SARS ... gives us concern that that may be the case here," the official said, adding however that there were "positive signs that they have taken action in Wuhan".

Fears of a pandemic initially spooked markets but they regained their footing on Wednesday, with investors citing the robust response from authorities as reassuring.

VIRUS SPREADING

The outbreak began in Wuhan, a major transportation hub as well as central China's main industrial and commercial centre, and has now spread to other major population centers including Beijing, Shanghai and Hong Kong.

There is no known cure for the virus. Symptoms include fever, difficulty in breathing and cough, similar to many other respiratory illnesses, and can cause pneumonia.

Chinese authorities are still investigating the origins of the virus, though they confirmed the outbreak began at a market in Wuhan with illegal wildlife transactions and that it can spread from one person to another via respiratory transmission. Among confirmed patients are 15 medical workers, further adding to worries about a possible global pandemic.

Many Chinese were canceling trips, buying face masks, avoiding public places such as cinemas and shopping centers, and even turning to an online plague simulation game as a way to cope.

Airports globally stepped up screening passengers from China and the European Centre for Disease Control and Prevention (ECDC) said in a risk assessment that further global spread of the virus was likely.

Britain joined other countries including Australia in advising citizens against all but essential travel to Wuhan.

Italian researchers have claimed that they have successfully developed a vaccine to contain coronavirus (COVID-19) which is likely to work on humans, a report said.

Luigi Aurisicchio, CEO of Takis, the firm developing the medication, said that a coronavirus candidate vaccine has neutralised the virus in human cells for the first time, the Arab News reported.

"This is the most advanced stage of testing of a candidate vaccine created in Italy. Human tests are expected after this summer," Aurisicchio was quoted as saying to Italian news agency ANSA.

"According to the Spallanzani Hospital, as far as we know we are the first in the world so far to have demonstrated neutralisation of the coronavirus by a vaccine. We expect this to happen in humans too," he added.

The researchers experimented with the vaccine on mice that had successfully developed antibodies that blocked the virus from infecting the cells. They further observed that the five vaccine candidates generated a large number of antibodies, and selected two with the best results.

All of the vaccine candidates currently being developed are based on the genetic material of DNA protein "spike", the molecular tip used by the coronavirus to enter human cells.

They are injected with the so-called "electroporation" technique, which consists of an intramuscular injection followed by a brief electrical impulse, helping the vaccine break into the cells and activating the immune system, the report said.

Researchers believe that this makes their vaccine particularly effective for generating functional antibodies against the "spike" protein, in particular in the lung cells, which are the most vulnerable to coronavirus.

"We are working hard for a vaccine coming from Italian research, with an all-Italian and innovative technology, tested in Italy and made available to everyone," Aurisicchio was quoted by the Arab News report.

"In order to reach this goal, we need the support of national and international institutions and partners who may help us speed up the process," he noted.

The total number of COVID-19 infections, fatalities and recoveries since the pandemic began has risen to 213,013 in the country.