Pakistan, Jan. 26 -- British police arrested 86 people on suspicion of aggravated trespass after protesters breached the grounds of a prison in west London during a demonstration in support of a Palestine Action activist, authorities said on Sunday.

The Metropolitan Police said the arrests were made Saturday evening outside HMP Wormwood Scrubs, where demonstrators gathered to protest the detention of a prisoner reportedly on hunger strike.

Police said the group refused to leave when ordered, blocked prison staff from entering and leaving the facility, and made threats toward officers. Some protesters also gained access to a staff entrance area of one of the prison buildings, according to authorities.

A spokesperson for the Justice Mini...