Around 100 to 200 pro-democracy protesters were barricaded inside a Hong Kong university Tuesday morning in a tense standoff with police. They're facing desperate conditions after battling police Monday with Molotov cocktails, catapults and bows and arrows, CBS News correspondent Ramy Inocencio reports.

In the makeshift infirmary at the Hong Kong Polytechnic University, volunteer medics said they've treated more than 100 injuries, including a collapsed lung from an officer's rubber bullet. Food supplies are dwindling but cooks in the canteen keep frying up rice to feed the last of the resistance.

There were hundreds of Molotov cocktails on the campus, and the smell of the flammable material was strong.

As the violence intensified Monday, protesters tried to escape in different ways, descending over bridges or dropping into dirty sewers. But on Tuesday afternoon, many of them, cold, hungry and wrapped in thermal blankets, surrendered and walked off campus.

Others, like two who identified themselves as John and Jacky, chose to stay.

"How are you feeling right now after three days being here?" Inocencio asked.

"Done. Very done," John said.

"Do you feel that you've lost?" Inocencio asked.

"This university is not the last battle," Jacky said.

"Because there is just another battlefield," John said.

Anyone under 18 years old was allowed to go home, but anyone 18 and older was immediately arrested by police. Chief Executive of Hong Kong Carrie Lam said 400 adults have been arrested so far. They could be detained and charged, but if they aren't charged, they could be set free.