Rioters set fire at an overhead bridge connecting the Hong Kong Polytechnic University and Hung Hom MTR station on Sunday. (Photo from Global Times/Web)

The Hong Kong Police Force denies accusations that it "raided" the premises of the Hong Kong Polytechnic University (PolyU) in an overnight standoff between masked rioters.

Clarifying in a media release on Monday morning, the police slammed the rumor as "totally false."

Rioters gathered Sunday at PolyU and set fire to the flyover connecting the campus and the Hung Hom MRT station.

Till 5:30 a.m. on Monday morning, fires and explosions were still seen and heard inside PolyU as police tried to conduct dispersal and arrest operations.