Ten Palestine Action activists have been arrested on suspicion of terror offences, police have said.
The arrests relate to the attack on Israeli defence firm Elbit Systems in south Gloucestershire in August.
Shortly after the incident on August 6, ten people were arrested and charged that same month. All ten were charged with criminal damage, aggravated burglary, and some were charged also with violent disorder and assault offences. They remain in custody awaiting trial.
On Tuesday, ten further people were arrested in connection with the attack; nine on suspicion of the commission, preparation and instigation of acts of terrorism, while a 72-year-old man from Hull was arrested on suspicion of preparation of terrorist acts, Counter Terrorism Policing South East said.
In the incident, activists were alleged to have rammed a large vehicle through the fence of the defence technology site and into the entrance of the building.
Video footage released by Palestine Action claimed to show people attacking equipment in the facility with crowbars and sledgehammers and spraying the walls of the building with red paint.
“Employees of the business who attempted to intervene were assaulted by the offenders with weapons,” Avon and Somerset Police said in a statement at the time.
Two officers were also assaulted with a sledgehammer.
Sledgehammers, axes, whips and other homemade weapons left behind by the offenders were seized by the police.
“The criminal damage is bad enough but to attack people with weapons is outrageous,” Superintendent Paul Wigginton said.
Police have said that the ten new arrests were in relation to the ongoing investigation into the incident in August, and all remain in custody.