Protestors smashed windows at a courier firm it claims is linked to an arms factory.
Anti-war campaigners Smash EDO published a hit list of firms associated with Brighton weapons manufacturer EDO/MBM earlier this year.
The Hove base of courier company DHL, which is at the top of the list, has been attacked twice in five weeks.
Five windows were put through in the early hours of Friday.
Daubed in paint on the car park were the words: "DHL deals with EDO MBM/ITT".
Smash EDO is a "direct action"
group targeting EDO MBM Technology, which it claims supplies weapons components in illegal military actions.
The group recently claimed it was being victimised by police when a film about its campaign was cancelled at short notice before a Brighton screening.
The Duke of York's Cinema pulled the film because it did not have a certificate.
Smash EDO's tactics have included protesters gluing themselves to the factory gates and singing karaoke badly to distract workers.
The group dumped horse manure at the front gate of US company ITT Corporation when it took over EDO MBM recently.
In February the group posted a list of companies which work with EDO on its website.
It read: "We believe if these companies and their employees are informed of their role and enough pressure is put on them we can stop them delivering services to the factory and isolate EDO."
An anonymous contributor to the protest website indymedia.org.
uk reported the vandalism in Hove on Friday with the message: "DHL should not deal with a cooperation sic whose profits are born from the deaths of innocent civilians."
Police were called at 1.30am on Friday. Two people had been seen running away down Fonthill Road. Forensics officers examined the scene and detectives studied CCTV footage. The centre was also targeted last month when vandals threw red paint at the building.
A spokeswoman for DHL said: "This incident has been reported to the police and is currently under investigation. For legal reasons we are unable to provide any further comment at this time.
"It is DHL's policy not to comment on our customer list."
A spokeswoman for Smash EDO said the group was not behind the vandalism. She said: "As a campaign we are not involved in anything like that."
She said the group has contacted DHL to ask it to stop working for EDO.
Anyone with information about the vandalism is asked to call Sussex Police on 0845 6070999 or Crimestoppers anonymously on 0800 555111.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article