The Hong Kong police arrested 1,377 people said to have been involved in violent incidents during the Hong Kong Polytechnic University (PolyU) standoff, officers told a news conference on Friday.

A police officer gathers forensic evidence at the Hong Kong Polytechnic University, Hong Kong, China, November 28, 2019. (Photo: CGTN)

The police said a search of universities in the city found nearly 10,000 petrol bombs. In the most recent operation, 12 officers were injured. A total of 483 officers were injured over the whole security operation.

A total of 5,890 people have been arrested amid the unrest in the Hong Kong Special Administrative Region (SAR), including 4,368 males and 1,522 females, on various charges, including unlawful assembly, possession of an offensive weapon and criminal damage, according to the police.

Since the beginning of November, Hong Kong's universities have been occupied and damaged. In some cases they became weapons arsenals for protesters.

Last week, rioters attacked the Chinese University of Hong Kong (CUHK) and threw debris onto the street, leading to road closures.

When the rioters left CUHK, they dispersed to different universities, making petrol bombs at PolyU and burning a toll station at the Cross-Harbor Tunnel.

"The police have taken control of the PolyU area to prevent further damage. We always hope to resolve this issue peacefully and flexibly," said the police.