LARNACA, Cyprus — A criminal court on Tuesday found a former defense minister guilty of manslaughter in the 2011 explosion of confiscated Iranian munitions that killed 13 people and badly damaged the country’s main power station.
The three-judge panel ruled that Costas Papacostas, 73, was responsible for the safeguarding of some 80 gunpowder-filled containers and was aware of the dangers posed by the munitions, but failed to take action to prevent the detonation.
A public inquiry into the causes of the blast found that the gunpowder had spontaneously combusted after becoming unstable from prolonged exposure to wide temperature swings.
The containers had been left piled on top of one another in an open field inside a naval base for more than two years.
The gunpowder was seized in February 2009 from a Cypriot-flagged ship suspected of transporting them from Iran to Palestinian militants in Gaza through Syria in breach of a United Nations ban on Iranian arms exports.
The court said that nothing was done to eliminate the danger of a possible explosion, even after some of the gunpowder detonated in one container a week before the larger, fatal blast.
‘‘The danger and the warnings were such that the fact that no measure was ever taken while it was possible indicates such indifference as to constitute willful negligence,’’ the judges said.
Papacostas was taken to Nicosia General Hospital after strong chest pains shortly after entering Cyprus’s central prisons complex, where he is to remain until his sentencing later this month.