Campaigners opposed to Israel's bombing of Lebanon have been protesting at the gates of a factory claiming it supplies weapons parts to the Israeli military.
Three protesters from Smash EDO chained themselves to concrete-filled barrels at the EDO MBM Defence Systems factory in Brighton, Sussex, early on Monday.
A spokesman for the group said their action had prevented vehicle access and slowed down production.
No-one from EDO MBM was available for comment about the protest.
The defence systems firm designs, develops and manufactures weapons components at its premises in Home Farm Road.
One of the protesters, Robert Frost, 26, from Manchester, claimed EDO provided guidance systems to Israel "probably being used in the bombardment of civilians in Lebanon as well as the Gaza Strip".
The other protesters were Martin Hill, 30, from Brighton, and Sarah Harris, 28, from Manchester.
Smash EDO has campaigned against EDO in Brighton since the start of the second Iraq war.
EDO recently failed to secure an injunction in the High Court to ban such protests.
Sussex Police said up to 20 officers were monitoring the protest.