Hong Kong police have arrested or put on record 1,300 people as of 11 pm on Tuesday in connection with the three-day siege at Hong Kong Polytechnic University.

Those detained face charges that include rioting and possession of offensive weapons. Radical students and rioters have used the university campus as a stronghold, firebombing a police armored vehicle and piercing the calf of an officer with an arrow as they engaged in a protracted battle with police.

Of the 1,300, about 800 walked out and gave themselves up, including 500 adults, who were arrested upon stepping out of the campus, and 300 under 18 years of age who had their photos taken and their personal information registered pending further investigations, according to police.

At a news briefing on Tuesday, Chief Superintendent Kwok Ka-chuen of the Police Public Relations Branch said the police have always wanted to end the standoff in a peaceful and humanitarian manner, adding that under no circumstances will the police initiate the use of force.

The police also revealed they have seized up to 3,900 gasoline bombs from the campus of the Chinese University of Hong Kong. The campus was also occupied by radical protesters for four days last week, as they fought intense battles with the police and blocked off Tolo Highway.

The gasoline bombs could last as long as 11 hours if one is hurled every 10 seconds, according to Kwok.

He said the police have every reason to believe that the vast arsenal of gasoline bombs stored on the PolyU campus and which were used extensively by rioters in clashes with the police over the weekend could surpass that seized from the CUHK.

"No one is above the law. No excuse, political demand or motive can spare anyone from legal liability," Kwok said, adding that lawbreakers will have to face the consequences.

The police fired 1,458 rounds of tear gas, 1,391 rubber bullets, 325 bean bag rounds and 265 sponge-tipped bullets in clashes with rioters on Monday to contain the situation, during which six officers were injured.

Meanwhile, Hong Kong's newly appointed police commissioner, Chris Tang Ping-keung, pledged on Tuesday to continue upholding the law and restoring order.

Tang made his debut at Police Headquarters in Wan Chai after being appointed by the State Council as Commissioner of Police of the Hong Kong Special Administrative Region.

Addressing the media, Tang vowed to fulfill the responsibilities of his new position, including protecting colleagues and supporting them to continue enforcing the law.

"Saddened" by the radicals' acts that defy and undermine the rule of law, he said that, in the past five months of turmoil, rioters had set fires to buildings, blocked roads, vandalized public and private facilities, and attacked police officers and residents.

He urged the radicals to stop the violence, and hoped the public will continue to support the police in restoring order in the community as soon as possible.

Chief Executive Carrie Lam Cheng Yuet-ngor on Tuesday vouched for the new commissioner's merit and, in a release, recognized Tang's "extensive experience" in criminal investigations, international liaison, and operational command.