AP Photos: University a battleground in Hong Kong protests

HONG KONG (AP) — For more than two weeks a Hong Kong university was transformed, first into a protester fortress with slingshots to fire gasoline bombs, then a city under siege with police arresting anyone who came out.

The police departed on Friday, taking with them nearly 4,000 gasoline bombs and leaving perhaps a few protesters still hiding in the warren of buildings 12 days after the siege began.

Protesters took over the urban campus in mid-November, using bricks to block surrounding streets as part of a campaign to disrupt traffic around the city. They turned the campus into a base, making weapons and setting up first aid stations and meal service in the cafeteria.

The police advanced on protester defenses in surrounding streets on a Saturday night and all day Sunday, bombarding them with tear gas and water cannons. Protesters wielded a wall of umbrellas on the front line and threw barrages of gasoline bombs, driving back an armored police vehicle in flames.

As the protesters retreated into the campus, the police set up a cordon that night. They warned that everyone inside could be charged with rioting.

Several groups tried to escape the next day, only to be driven back by tear gas. Some came out and turned themselves in to police. Others tried daring escapes through sewers or rappelling down from overpasses to waiting motorcycles. It’s not clear how many got out, but most either surrendered or were caught.

Several dozen held out as the siege dragged on into its second week. After 12 days, the police pulled out and university officials began contemplating the task of cleaning up and repairing a heavily damaged campus, walls covered with graffiti messages, a rotting stench and scarred areas burnt by fires.