Protesters clashed with police in chaotic scenes as dozens fled Hong Kong Polytechnic University in Kowloon, leading to multiple arrests and injuries, as a standoff continued in the heart of the city.

Police earlier called on demonstrators to drop their weapons and leave in an orderly manner, warning that live ammunition could be used. Riot police are still surrounding the area, where about 600 protesters are estimated to be holed up. Running battles have occurred, with police firing tear gas and rubber bullets at demonstrators who threw bricks and molotov cocktails while hiding behind umbrellas.

The chaotic scenes came as Hong Kong braced for yet more disruption after protests left the city paralyzed much of last week. Demonstrations seeking greater democracy in the Beijing-controlled territory have become increasingly violent in recent weeks, with protesters vandalizing transportation networks and China-friendly businesses as they push for demands including an independent inquiry into police violence and the ability to nominate and elect the city’s leaders.