"A discrepancy has been discovered between projected and actual military equipment at the Leros naval technical installation," navy spokesman Michail Lambiris said in a statement.

"Army and police authorities are investigating," he said.

The discovery was made on Monday during an inventory check, Lambiris said.

The navy did not give details but reports said the missing weapons included armour-piercing rounds and grenades.

Greece's anti-terrorism squad was also part of the probe, state TV ERT said.

Weapons have been stolen from Greek military installations in the past.

Far-left outfit November 17 made off with rockets, detonators, grenades and bullets from an army camp in central Greece in 1989. The group was broken up by authorities a few years later.