(CNN) -- An explosion in a southern Iranian mosque that killed 10 people and wounded 160 after evening prayers Saturday night was caused by negligent handling of live munitions, not a bomb as first suspected, Iranian media reported.

Shiraz, Iran, is well known for being home to many scholars, artists and poets.

The blast and subsequent fire occurred about 6 p.m. Saturday in the men's section of a mosque in the city of Shiraz, Iran's Fars news agency reported.

Fars initially reported the explosion was caused by a home-made bomb.

Provincial Police Commander Ali Moaeyri later told Fars it "was not sabotage."

"Some live munitions may have been left behind at that location which could have been the cause of the explosion," Moaeyri said.

The police commander said the munitions were apparently left behind after a "Sacred Defense" exhibition was held at the mosque, which also serves as a cultural center.

Local militia groups -- known as Basij -- often use the mosques for meeting places.

Iran's official news agency, IRNA, put the number of casualties at 10 dead and 160 wounded. Survivors were being treated at 12 hospitals, IRNA reported.

Fars estimated 800 people, mostly young, were gathered at the mosque Saturday evening to hear a cleric's sermon denouncing Bahai and Wahabi faiths -- both of which are considered heresies by some Shiites.

Bombings are unusual in Iran, thought the predominantly Shiite Muslim country has endured sporadic attacks in recent years.

The last major bombing occurred in February 2007, when a car bomb blew up near a bus carrying members of Iran's Islamic Revolutionary Corps, leaving a dozen dead and injuring dozens more in southeastern Iran.

Shiraz -- a historical city of more than 1 million people -- is well known for being home to many scholars, artists, poets and local craftsmanship of rugs and metalwork. The tourist city is about 400 miles south of Tehran, the capital. E-mail to a friend

Journalist Shirzad Bozorgmehr contributed to this story.

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