Hong Kong police have fired tear gas and rubber bullets to force back anti-government protesters trying to escape a university, in which hundreds of people are holed up with petrol bombs and homemade weapons amid fears of a bloody crackdown.

Dozens of people attempted to flee the Polytechnic University campus on Monday after a night of chaos in the Chinese territory, during which a police officer was shot with a bow and arrow, major routes were blocked and a bridge set on fire.

Protests have been raging in the former British colony for six months at first in opposition to a highly controversial extradition bill , which could have seen Hong Kong residents detained in mainland China.