Pro-democracy protesters have clashed with riot police outside the headquarters of Hong Kong's government.
Government offices and shops were forced to temporarily close while the stand-off continued.
British lawmakers will not be allowed to enter Hong Kong as part of an inquiry into Britain's relations with its former colony and progress towards democracy there, the head of a parliamentary committee said.
"I have been informed by the Chinese Embassy that if we attempt to travel to Hong Kong we will be refused entry," foreign affairs select committee chairman Richard Ottaway said in a statement.
The committee is looking at Britain's relations with Hong Kong 30 years after it agreed terms for handing the city over to China.
The news comes as thousands of pro-democracy activists in Hong Kong have clashed with police over the way the city's next leaders will be elected in 2017.
The Democratic presidential candidate may also have shown his cards on his choice of running mate.
The US president also shared a post on Twitter accusing Dr Anthony Fauci of misleading the public over hydroxychloroquine.
Fears over an impending second wave of coronavirus dominates Wednesday’s front pages.