KUFA, June 7: Two Iraqis were killed and at least nine wounded on Monday in a mystery explosion inside Kufa's Great Mosque compound, a stronghold of Shia leader Moqtada Sadr and his Mehdi Army militia.

A Sadr aide blamed the blast on an electrical short that ignited chemical materials stockpiled there for renovations, although witnesses said a rocket hit a weapons cache used by militiamen.

It exploded and caught fire, triggering multiple explosions, they said. "At 11 this morning, there was a big explosion in the holy mosque of Kufa. The explosion was huge and the flames of smoke rose above the walls," said Sadr official Sheikh Ahmed Shaibani.

"An investigative committee concluded the explosion was caused by an electrical short inside the main mosque where chemical materials used for reconstruction were being stored," the sheikh said.

He denied that any weapons were kept inside the place of worship. The Great Mosque in this city south of Baghdad is where Sadr delivers his sermons at weekly Friday prayers. Its surroundings have been the scene of deadly clashes between his militia and US troops over the past two months.

A doctor at the Mohammed Baqr al-Hakim hospital put the death toll at two, while the nearby Furat al-Wasat hospital said nine Iraqis were wounded, without specifying whether they were gunmen or civilians.

An AFP photographer said eight chambers in the mosque compound, alongside the shrine, were completely destroyed by the fire and force of the blast. In one of the rooms, a crater one-metre deep and up to four metres wide had been gouged out of the ground.

The US military confirmed an explosion had taken place and that part of the mosque caught fire. -AFP