Fiery clashes erupted across the city, with security chief John Lee cautioning "unthinkable" consequences if the violence continued.
Authorities have shut down schools, rail links and several businesses in the Asian financial hub as a safety precaution.
On Tuesday night, hundreds of black-clad protesters tried to block riot police from entering the Chinese University of Hong Kong (CUHK) near Tai Po by hurling bricks and petrol bombs.
Trump says no Israeli troops will go to Beirut after call with Netanyahu
US President Donald Trump said on Monday that Israel would not send troops to Beirut after a call he held with Israeli Prime Minister Benjamin Netanyahu.
Iran halting indirect talks with US over Israel's Lebanon incursion
Iran is halting indirect negotiations with the US after Israel ordered troops to push deeper into Lebanon to battle Tehran-backed Hezbollah, the Iranian news agency Tasnim said on Monday, complicating diplomatic efforts to end three months of war.
Trump says Iran really wants to make a deal with the US
President Donald Trump on Monday said that Iran really wanted to make a deal with the US and that it would be a good one for Washington and its allies.
Israel's Netanyahu orders attacks in Beirut's southern suburbs
Israeli Prime Minister Benjamin Netanyahu ordered attacks on the Hezbollah-controlled southern suburbs of Beirut on Monday, signalling further escalation of a war that has complicated mediation towards resolving the US-Iran conflict.
Malaysia bars under-16s from signing up for social media
Malaysia has begun barring those aged under 16 from registering accounts on social media platforms, its communications regulator said on Monday, as it boosts efforts to protect minors from exposure to harmful content online.
