Palestine Action claims to have blockaded the UK headquarters of an Israeli defence company in Bristol, as the group faces an imminent ban under anti-terror legislation.
Activists with the direct action group blocked the sole entrance to Elbit Systems on Tuesday, covering it in red paint "to symbolise Palestinian bloodshed", a spokesperson said.
The group claimed it was "successfully disrupting" business-as-usual at the site.
Separately, the spokesperson added that activists also occupied the rooftop of UK subcontractor Guardtech Group in Suffolk.
The action comes after a draft order was laid before Parliament on Monday, seeking to amend the Terrorism Act 2000 to proscribe Palestine Action.
If approved, the legislation would make it a criminal offence, punishable by up to 14 years in prison, to be a member of or support the direct action group.
MPs and peers are scheduled to debate the proposed ban on Wednesday and Thursday.
Should it pass, the proscription could come into force as early as Friday.
A Palestine Action spokesperson said: “While the Government is rushing through Parliament absurd legislation to proscribe Palestine Action, the real terrorism is being committed in Gaza.
“Palestine Action affirms that direct action is necessary in the face of Israel’s ongoing crimes against humanity of genocide, apartheid, and occupation, and to end British facilitation of those crimes.”
A spokeswoman for Avon and Somerset Police said officers were called to the Bristol site of Elbit Systems at around 6.30am on Tuesday.
“Officers are responding to a protest involving two people at a premises at the Aztec West Business Park, in Almondsbury,” the spokeswoman said.
“We’re committed to facilitating people’s right to peaceful protest, but will not tolerate any criminal behaviour.”
Palestine Action is seeking a legal challenge against the Government’s bid to proscribe it.
A hearing expected on Friday to decide whether the ban can be temporarily blocked, pending further proceedings to decide whether a legal challenge can be brought.
Commenting on the proscription on Monday, Home Secretary Yvette Cooper said: “The right to protest and the right to free speech are the cornerstone of our democracy and there are countless campaign groups that freely exercise those rights.
“Violence and serious criminal damage has no place in legitimate protests.”
Suffolk Police have been contacted for comment.
