Four activists entered the site at 5am on Thursday and began dismantling electronic equipment, air conditioning systems and windows. They also covered the premises in trademark red paint in a move to symbolise the blood spilt with Leonardo weapons.
The activists targeted the Crewe Road North site in Edinburgh in what they said was an aim to cause maximum disruption against the company that supplies a range of military equipment and targeting systems.
A police helicopter attended the scene of the protest. A Police Scotland spokesperson said: “Police were called to a report of a protest at a building on Crewe Road North in Edinburgh around 7.50am on Thursday, 19 January.
“Damage was caused to the building. Two men, aged 28 and 22, and a 28-year-old woman, have been arrested in connection with the incident and enquiries are ongoing.”
The Edinburgh site is a world leader in the high-energy military laser market, with the targeting systems rigged to a number of planes, such as F-35 fighter jets, which have been used by Israel.
The protest follows a similar demonstration at Thales' factory in Glasgow in July last year, against the French weapons company partnered in the manufacture of Elbit Systems drones.
A spokesperson from Palestine Action Scotland stated: "We've taken on Thales and now we've taken on Leonardo. Any company supplying Israel should be well aware by now that Scotland is not a safe place for them to conduct their deadly trade.”