Computer hackers last week hit the website of Lockheed-Martin, the supplier of F-35 warplanes to Israel. The Pentagon says security was not breached, but data was stolen.

Classified information was not breached because it is kept on a separate server, a former American defense official told Reuters. Theft was ”minimal and we don't expect any adverse effect," a Pentagon official said.

The invasion of the company’s site came shortly after reports that the Israel wants to speed up deployment of 20 of the F-35 stealth fighter planes that been ordered from Lockheed-Martin.

PC World reported that that an attack on the site several months ago compromised SecurID keys as part of a strategic move to steal the computer keys to the RSA security network.

“The attack against RSA Security does not appear to have been a random crime of opportunity, but rather a targeted attack calculated with the goal of acquiring the keys necessary to tackle larger prey like Lockheed-Martin,” according to PC World.

Last month, Lockheed-Martin dismissed claims that Chinese computer spies hacked its top-secret files on the F-35. Australia also has ordered the stealth fighter.