HONG KONG (Reuters) - Hong Kong police said they would enter Polytechnic University on Thursday after a two-week siege drove most protesters out, but just before midnight, a masked man emerged and asked them to halt their plan.

Security teams from the university had scoured the maze of buildings at the campus, a focal point in recent weeks of the citywide protests that first erupted in June, finding no one.

Yet the protester, who appeared in a black mask, said about 20 people were still hiding. “If the police retreat, we would leave,” he told reporters.

Earlier in the day, District Commander Ho Yun-sing said police planned to enter the campus to “process dangerous items and collect evidence” and that any remaining protesters would be given medical treatment.

The university on Kowloon peninsula was turned into a battleground in mid-November, when protesters barricaded themselves in and clashed with riot police in a hail of petrol bombs, water cannon and tear gas. About 1,100 people were arrested last week, some while trying to escape.

Riot police sealed off the campus, setting up high plastic barricades and a fence on the perimeter.

The Polytechnic University campus was the last of five that protesters had occupied to use as bases from which to disrupt the city, blocking the nearby Cross-Harbour Tunnel linking Kowloon to Hong Kong Island and other arteries.

The protesters had blocked the tunnel’s mouth, smashed toll booths, lit fires and cemented bricks to the road, but it was reopened early on Wednesday, and Hong Kong television showed a steady flow of vehicles passing through.

Demonstrators are angry at what they see as Beijing’s meddling in the freedoms promised to the former British colony when it returned to Chinese rule in 1997.

China denies interfering and says it is committed to the “one country, two systems” formula put in place at that time.

CALL FOR HUMANE APPROACH

The university on Wednesday asked government departments for help removing “dangerous materials” from the site, which is littered with rotting waste and detritus of the siege, requesting authorities take a “humane” approach.

The number of protesters inside had dwindled dramatically, with some managing to flee and others brought out in what rescuers said was vulnerable state.

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The city’s largest pro-establishment party, the Democratic Alliance for the Betterment and Progress of Hong Kong, said the government should send medics to the site to take any remaining protesters to hospital.

Hong Kong authorities hope that a lull in clashes over the weekend during local elections, where pro-democracy candidates scored a landslide victory, can translate into more calm after nearly six months of turmoil.

But a “Thanksgiving” protest, in appreciation of the U.S Congress passing legislation supporting protesters, is scheduled for Thursday, the date of the U.S. holiday, and others were planned for the weekend, including against the use of tear gas.

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Secretary for Security John Lee said on Wednesday police had arrested more than 5,800 people since June, the numbers increasing exponentially in October and November, and had charged 923.

Smaller scale protests continued on Wednesday, as crowds in the central business district took to the streets around noon.

The city-wide elections drew a record turnout and were seen as a vote of no-confidence in Hong Kong’s Beijing-backed leader, Carrie Lam, over her handling of the financial hub’s worst crisis in decades. Lam called for calm and said she would seriously reflect on the results.

One Hong Kong newspaper, Sing Pao, published a front-page spread for the second successive day calling for Lam’s resignation. “Hong Kong people had enough, Carrie Lam quit,” it read.