What happens at the Hong Kong University standoff between protesters and police?

A standoff at the Polytechnic University in Hong Kong continues after students barricaded themselves inside during anti-government protests.

Some desperate students attempted to flee, but police appeared to trap them inside the university by firing tear gas and rubber bullets on those who tried to leave.

Up to 800 protesters gathered on the campus, some of them carrying homemade weapons such as Molotov cocktails. Police threatened to use live amunition if they failed to disarm themselves.