Six Palestine Action activists entered an Israeli-linked arms factory intending to smash up as much property as possible before police arrived, a court has heard.

Prosecutor Deanna Heer KC said the defendants used sledgehammers and crowbars to destroy drones manufactured by Elbit Systems and computers at its factory in Filton, near Bristol, on 6 August last year.

She said one of the accused, Samuel Corner, 23, “went further than simply using a sledgehammer to destroy property. When the police arrived, as the defendants fully expected them to, he used his sledgehammer to assault them.”

Charlotte Head, 29, Corner, Leona Kamio, 30, Fatema Rajwani, 21, Zoe Rogers, 22, and Jordan Devlin, 31, are all charged with criminal damage, with Corner also charged with causing grievous bodily harm with intent to Sgt Kate Evans, who suffered a fractured spine, the court heard. They all deny the charges.

Opening the trial at Woolwich crown court on Wednesday, Heer said: “Once inside the factory, their job was to smash up as much property as they could and to keep smashing until the police arrived to arrest them.

“And that is what they did. They had with them an array of tools in order to do so, including crowbars and sledgehammers. The sledgehammers each weighed 7lb (3.2kg). They were capable of causing a considerable amount of damage and were used to cause a considerable amount of damage to the factory.”

The court heard that, at 3.30am on the day in question, a van carrying the defendants crashed through the fence surrounding Elbit’s factory, followed by 12 members of Palestine Action wearing black jumpsuits shouting “Free Palestine”. The “black team” were armed with smoke grenades, flares and fireworks, as they sought “to overwhelm security guards so that the red team could break into the factory”, said Heer.

The van was driven into the loading bay shutter until it gave way. Once the defendants, who were wearing red jumpsuits, were inside, as well as using crowbars and sledgehammers to destroy property, they sprayed the walls and floor with fire extinguishers filled with red paint, the jury heard.

Heer told the court that when police arrived, PC Aaron Buxton sprayed his Pava spray (similar to pepper spray) towards Corner and Devlin and ended up on the floor with the latter, who was on top of him. She said Corner struck Buxton twice before walking over to Evans who was on all fours, facing away from him, attempting to arrest Rogers.

“He raised his sledgehammer over his head and brought it down forcefully over her back,” said Heer. “Having hit her once, he raised it again and hit her with it a second time … She screamed in pain. She was immediately terrified that her spine had been damaged and when she tried, she was unable to get up.”

The court heard that Evans was unable to return to work for three months, still experienced pain and has been confined to restricted duties.

Heer said that planning documents found on an encrypted website indicated that the purpose of the attack was to “Shut Elbit Down. This is our primary objective as Palestine Action. We can do that by sticking together and ensuring its destruction with our brains and muscle.” One document said that if security guards got in the way, the group should continue, “louder, angrier and more determined”.

The trial continues.