Markos Kyprianou, an influential member of the junior party in Cyprus's left-wing coalition, said he had tendered his resignation to President Demetris Christofias. It was unclear whether it would be accepted. The government is looking increasingly vulnerable in the wake of the blast that killed 13.

"I hear the public, and I want to contribute to the restoration of trust in the political system at such a crucial time for Cyprus," Kyprianou, a former European commissioner, told reporters.

He would be the second minister to quit after a massive blast in a confiscated cargo of Iranian munitions last week, destroying Cyprus's largest power station. The defence minister and the army chief resigned on July 11.

Normally placid Cypriots have taken to the streets in their thousands in a show of anger over an incident widely perceived to be the result of incompetence and negligence.

Kyprianou's ministry was involved in confiscating and handling the cargo, which blew up after more than two years stored in scorching temperatures in a military base.

"I plan to ask the President of the Republic to excuse me from my duties as foreign minister, not because there is a feeling of guilt, but out of sensitivity," Kyprianou said. He said he endorsed an impartial investigation.

The huge explosion, equivalent to a 1.5 megaton bomb, ripped through a navy base and destroyed a 700 million euro power plant generating more than half the island's electricity.

A third of Cypriots quizzed in a weekend poll said they believed Christofias should resign over the disaster. He was elected in 2008 for a five-year term.

Cyprus confiscated the munitions from a ship sailing from Iran to Syria in 2009, citing a breach of U.N. sanctions. U.S. diplomatic cables published by WikiLeaks suggested that Nicosia acted under strong U.S. pressure and resisted pressure from Syria and Iran to let the boat sail unhindered.

The 98 containers, whose contents were never fully disclosed, were stored in an open field at the base next to Vassilikos, Cyprus's main power station, a site where temperatures soar in the Mediterranean summer.

The daily Politis said the foreign ministry had failed to respond to a request by U.N. weapons inspectors in January to inspect the cargo.
Christofias himself was unaware of the deteriorating condition of the munitions, government officials have said, although the army had repeatedly appealed for their removal.

The attorney general has ordered a criminal investigation into the incident. Christofias has said an inquiry would also scrutinise his own role in the affair.