A hard-core group of 100 protesters occupying a Hong Kong university are still holed up inside campus buildings, after some 600 surrendered overnight in a deal brokered by representatives of the opposing sides. Hong Kong Chief Executive Carrie Lam said that, of those who surrendered to authorities at the Polytechnic University campus in Kowloon, 400 were arrested and 200, who were children, were not. An additional 20 activists were evacuated to seek medical help. Tens of thousands of people have taken to the streets in the last three days in an attempt to reach the protesters at the university and show their solidarity with them, prompting the most prolonged and violent clashes of the protests so far. Riot police have fired tear gas, rubber bullets, and even live rounds. About 200 people have been injured. On Monday, a Hong Kong court ruled that a ban on face masks was unconstitutional, a decision authorities in Beijing condemned on Tuesday.