HONG KONG, Nov. 23 (Xinhua) - The Hong Kong police on Saturday appealed to those staying in the Hong Kong Polytechnic University (PolyU) to leave the campus in a peaceful manner.

(Photo: Xinhua)

The police said in a statement that they have all along emphasized two principles: peaceful resolution and flexibility, reiterating that for those under 18 years old they would "arrange an appropriate adult to accompany them."

"All underage persons leaving the campus are required to have their personal particulars registered and to be photographed," the police said. "They will not be arrested at scene but police reserve every right to pursue or take any legal actions in the future."

From Sunday afternoon, rioters gathering around PolyU have taken the campus as a stronghold to launch assaults on police officers, using lethal weapons including petrol bombs, bows and arrows, metal balls and bricks.

In the past few days the police have engaged with different sectors for dialogues and solutions, including PolyU staff, principals, social workers, lawyers, legislative councillors, religious leaders and clinical psychologists, the statement said.

Dozens of rioters are estimated to be still hiding on the campus and the police have repeatedly appealed to them to surrender. As of Tuesday, nearly 800 people had left the PolyU peacefully, with nearly 300 under the age of 18 who were released after having their personal data recorded.