Protesters locked and glued themselves to a factory entrance to mark the fifth anniversary of the invasion of Iraq.
Police made seven arrests at the EDO MBM Technology Ltd site in Home Farm Road, Brighton, yesterday.
Four demonstrators from the Smash EDO protest group used arm tubes and another four used bicycle locks to attach themselves to the entrance.
Firefighters used pneumatic cutters to release them from the locks.
Six people were arrested for aggravated trespass and one for criminal damage.
The protesters claim weapons manufactured by the company are used in acts of warfare which breach international law.
Tom Hayes, 29, said: "This is part of an ongoing campaign to ask people who work at the factory what has come out of five years of invasion and occupation in Iraq.
"It certainly hasn't benefited the people of Iraq, who will have been left completely traumatised by five years of conflict.
"It is only the oil companies and factories like this one which have really profited."
This week a screening of a film about the Smash EDO campaign was cancelled at the last minute after a police officer contacted Brighton and Hove City Council to point out the film did not meet licensing requirements for public screening.
The film must be certificated by the British Board of Film Classification before it is shown publicly.
Sussex Police confirmed a junior officer from outside the city had called the council.
A scheduled screening of the film at the New Park Centre in Chichester on Wednesday was also cancelled.
The centre confirmed it had pulled the film after staff realised it could no longer be shown as a private screening because it had been advertised on the internet.