As violence spread on Monday, police arrested over 260 people while deploying heavy security around Metro stations with riot police deployed across the city.
The Trump administration today expressed "grave concern" over the situation in Hong Kong which saw a student demonstrator being killed last week and another shot at during violent demonstrations on Monday.
"The United States is watching the situation in Hong Kong with grave concern," State Department spokeswoman Morgan Ortagus said in a statement.
On Monday, large scale clashes between police and protesters in various parts of the city led to escalation of violence in which one person was shot at as Hong Kong saw 24 weeks of continuous violence.
At Sai Wan Ho district police opened fire on a 21-year-old protester in the chest, the incident was broadcast live on facebook.
The police reportedly again opened fire, firing two more live rounds as another protester fell on the ground. Both protesters were detained, according to reports.
"We condemn violence on all sides, extend our sympathies to victims of violence regardless of their political inclinations, and call for all parties -- police and protestors -- to exercise restraint," the State Department said.
There were other incidents of violence across the city including in Lung Cheung Road, Connaught Central and Pedder Street.
Defending its action, Chief Superintendent of Police Public Relations Branch of Kwok Pak-Chung said: "Two-person approached and my colleague was blocked and his waist was held on, "Suddenly a man wearing black appeared...if you look at his right hand he is trying to snatch my colleague's gun with his right hand."
"Because of the threats from two directions, and he knew if his gun was snatched, his safety, as well as the bystanders near him, will be threatened, therefore he decided to open fire," he added.
As violence spread, police arrested over 260 people while deploying heavy security around Metro stations with riot police deployed across the city.
Meanwhile, Hong Kong leader Carrie Lam said that "the widespread violent acts (of protesters) should be condemned by the whole society," adding,"The action of rioters has far exceeded the call for democracy and are now people's enemy. And it is incidents like that, which has seen by many local residents, making people worried and scared."