HONG KONG, Nov. 22 (Xinhua) -- Tang Ping-keung, commissioner of police of China's Hong Kong Special Administrative Region, on Friday urged remaining rioters to leave the Hong Kong Polytechnic University (PolyU) campus as soon as possible, citing bad and dangerous conditions inside.

Tang told a media briefing that most of the rioters who had occupied the campus for days have been persuaded to leave, and the police worked very hard in the vicinity of the PolyU campus with some officers having been on duty for more than 30 hours in a row.

Under the threat from hundreds of petrol bombs, bricks and metal balls, officers enforced the law in harsh conditions, and a police media liaison officer was shot in the leg with an arrow, said Tang, who was appointed as the new Hong Kong police chief on Tuesday.

Police officers will continue to maintain order in Hong Kong without fear, he added.

During the standoff around the PolyU, the police have arrested some 1,100 people for offenses including taking part in a riot and possession of offensive weapons.