Cyprus' president is mainly to blame for events that led to the explosion of seized Iranian munitions that killed 13 people and caused a political and economic crisis on the island, the head of an official inquiry said Monday.

But President Dimitris Christofias rejected the inquiry's conclusion that he bears personal responsibility for the blast, saying it is not supported by the evidence that was given during weeks of public hearings and that he won't step down.

The finding is not legally binding, and Christofias cannot be impeached under the Cypriot Constitution, but the inquiry's findings have likely quashed his chances at re-election when his current term in office ends in February 2013.

Christofias conceded some political responsibility for the blast as head of state and he apologized for the "omissions, mistakes and weaknesses that led to the tragedy." But he said resigning now would lead the divided island "to a period of instability and tension."

Cyprus was split into an internationally recognized Greek speaking south and a breakaway Turkish speaking north in 1974 when Turkey invaded after a coup by supporters of union with Greece. Currently, Cyprus is trying to reboot a stagnant economy, invigorate stalled reunification talks, and cope with threats from Turkey about its offshore oil and gas exploration.

Polys Polyviou, who led the inquiry, said Christofias was primarily responsible for the "inadequacy, negligence and carelessness" that led to the July 11 blast at a naval base. But Polyviou said two government ministers also share some responsibility for the disaster.

The explosion wrecked Cyprus' main power station and sapped public trust in Christofias' presidency amid calls for him to resign. The blast's impact on the economy also stoked fears that the island could be forced to seek a bailout from its European Union partners.

"My conclusion is that the main responsibility for the tragedy weighs on the president of the republic," Polyviou, a legal expert, told a nationally televised news conference to present the public inquiry's nonbinding findings.

Christofias had testified at the inquiry hearings that he was never told by subordinates just how dangerous the munitions were. He also denied any personal responsibility and blamed the disaster on "a failure of the system." He said that although he consented to destroying any material thought to pose a danger, nothing ever happened.

But Polyviou said Christofias had "very serious personal responsibilities," adding that he should have known about the dangers involved with the munitions and showed "inexcusable negligence which resulted in the death of 13 people."

Christofias said many of Polyviou's conclusions "obviously, and at first glance, lack the necessary proof, are unfounded and even contradict presented evidence." He also accused Polyviou of exceeding his mandate by delving into the government's handing of foreign policy.

The munitions _ mostly gunpowder and some nitroglycerine stored in 85 containers _ were seized in February 2009 from a Cypriot-flagged ship suspected of transporting it from Iran to Palestinian militants in Gaza through Syria. The United Nations ruled that the ship had breached a ban on Iranian arms exports.

The containers had been left piled in an open field inside the base for 2 1/2 years, exposed to wide temperature swings on the Mediterranean island. Military officials had warned five months before the explosion about the possibility that the munitions could spontaneously ignite as a result of their exposure to the elements.

Polyviou called the munitions "a ticking time-bomb waiting to go off" and that it was incumbent on the president to take measures that would ensure the munitions' safe storage.

Christofias said there is no evidence proving that he was primarily responsible for the munitions' safekeeping or that he knew how dangerous it was.

Polyviou said Cyprus' ministers of foreign affairs and defense _ both of whom resigned because of the explosion _ also shouldered plenty of blame for the handling of the matter that was "left to the mercy of the usual bureaucratic procedures."

A Foreign Ministry official had served as the main liaison between Christofias and the two ministers regarding the stockpile.

"The essence of the matter is that the president of the republic, in this instance, failed in his duty to implement the necessary measures for the safety of the citizens of the Cyprus republic and especially its military and fire department personnel," said Polyviou.

A separate, police-led probe into the explosion is also expected to conclude soon.

Polyviou said he had no doubt that serious crimes _ including manslaughter _ have been committed as a result of the blast, but that was a matter for the attorney general to pursue.