HONG KONG (AP) — Police in Hong Kong are preparing to reopen access to a university campus after blocking it for 12 days to try to arrest protesters holed up inside.

Assistant Commissioner Chow Yat-ming said Friday morning that officers had almost finished a 1 ½-day operation to collect evidence and remove gasoline bombs and other dangerous materials from Hong Kong Polytechnic University.

He says they did not encounter any protesters. One masked protester told media before police came in that about 20 people were still hiding to avoid arrest.

They are the holdouts from roughly 1,000 protesters who had retreated inside the campus after battling police on the streets. A few escaped a police cordon, but police say they arrested 700 people and recorded the details of 300 minors.