A group of 86 protesters who allegedly breached prison grounds at west London’s Wormwood Scrubs jail have been arrested, the Metropolitan Police said.

The force said the group were “protesting in support of a Palestine Action prisoner on a hunger strike”, and allegedly threatened police and stopped prison staff from entering and exiting.

The Prisoners for Palestine campaign group identified the inmate as Muhammad Umer Khalid, 22, who they say began a thirst strike on Friday. He is awaiting trial over a break-in at RAF Brize Norton last June. He denies the charges.

All those involved will be arrested on suspicion of aggravated trespass after refusing to leave.

“A number managed to get inside a staff entrance area of a prison building,” the Met said.

A Ministry of Justice spokesperson said that “at no point was prison security compromised” and called the action an “escalation” that was “completely unacceptable”.

“While we support the right to peacefully protest, reports of trespassing and threats being made to staff and police officers are deeply concerning,” they said.

Prisoners for Palestine said Khalid has limb-girdle muscular dystrophy, a genetic condition, and was on an “extremely dangerous” thirst strike.