More than a quarter of those taking part in a protest in Brighton today were arrested.
Sussex Police said that nearly 40 people were taken into custody during the Smash EDO protest.
About 150 protesters took part in the demonstration, which they called Hammertime.
Most of the arrests were for breaching the peace or public order offences although one was for having “a bladed article” and two were for theft.
The demonstration was directed against EDO MBM Technology in Home Farm Road, Moulsecoomb.
The protesters object to EDO making part of the weapon systems which are used by the Israeli air force in Gaza.
Chief Superintendent Graham Bartlett, the officer in charge of policing the protest today, said: “Officers have made significant arrests this afternoon in order to prevent a further breach of the peace.
“Despite designating a highly visible site for protesters on the main road to the factory, many of them have not used it.
“Our aim today was to facilitate peaceful protest.
“Instead many have caused disruption by failing to comply with police directions, running away through fields and woodland and causing a disruption to local people.
“Their disorderly behaviour has put pressure on police resources as we have needed to contain them to curb further disruption.
“They have blocked major roads and headed towards other targets in the city.
“Given those arrested have been detained to prevent a breach of the peace, we anticipate that they will be released when the risk of a further breach has diminished.
“There have been more arrests than last year because of the disruption caused to the community.
“When this happens the public would expect us to act and that is what we have done today.
“Injuries have been caused by protesters running around.
“Police medics were quickly on hand to treat one woman who ran into railings and injured her knee before an ambulance arrived.
“The situation seems to be calming down and we are taking this opportunity to review the level of resources and standing some officers down.”
Some protestors made their way from the Home Farm Road area down Lewes Road to London Road and The Level.
A few disrupted traffic by wandering into the road.
Others ran through the Bates housing estate, including a woman who injured herself by running into a gate.
Sussex Police said that there had not been any serious disorder and that all local businesses – including EDO – had managed to work normally, although many drivers suffered delays.
A spokesman said that the force wished to allow protests to take place peacefully even though the organisers had not liaised inadvance with Sussex Police.
Some of the campaigners massed in Wild Park, while about 40 were reported to have emerged from a squat in Stanmer Park.
The squat is subject to a possession order granted by Brighton County Court on Monday.