Hong Kong police surround university where hundreds of protesters trapped

Police in riot gear move through a cloud of smoke as they detain a protestor at the Hong Kong Polytechnic University in Hong Kong, Monday, Nov. 18, 2019. Hong Kong police fought off protesters with tear gas and batons Monday as they tried to break through a police cordon that is trapping hundreds of them on a university campus. (AP Photo/Ng Han Guan)

Police in riot gear move through a cloud of smoke as they detain a protester at the Hong Kong Polytechnic University. (Ng Han Guan/Associated Press)

Nov. 18, 2019 6:53 AM PT

Protesters run for cover after riot police fired tear gas toward the footbridge they were climbing down to escape from the Hong Kong Polytechnic University campus. (Anthony Wallace / AFP / Getty Images)

A protester barricaded at the Hong Kong university prepares to shoot an arrow. (Anthony Wallace / AFP /Getty Images)

A pro-democracy protester uses binoculars during a march toward Hong Kong Polytechnic University in Hong Kong. (Fazry Ismail/EPA/REX/Shutterstock)

Protesters react as police fire tear gas in Hong Kong. As night fell Monday, police tightened a siege at the school where hundreds of anti-government protesters were trapped. (Vincent Yu / Associated Press)

Protesters climb over a bridge railing to a roadway below to escape police. (Ye Aung Thu / AFP / Getty Images)

Protesters use a rope to lower themselves from the pedestrian bridge to waiting motorbikes at Hong Kong Polytechnic University. (Kin Cheung / Associated Press)

A bystander affected by tear has his eyes rinsed amid clashes between police and pro-democracy protesters in the Jordan district of Hong Kong. (Migeul Candela/EPA-EFE/REX)