BAGHDAD - Up to 32 people were killed and 57 wounded in a twin suicide bomb attacks at a Shiite mosque in the Iraqi capital of Baghdad on Tuesday, an Interior Ministry source said.

"The toll rose to 32 killed and 57 wounded in the explosions which appeared to be carried out by two suicide bombers at al- Husseiniyah (Shiite mosque) in Baghdad," the source told Xinhua on condition of anonymity.

The attackers first shot dead the guards of the mosque by silenced weapons before they entered the mosque and blew up their explosive vests among worshippers during noon prayers at the mosque in al-Qahira district in northern Baghdad, the source said.

Earlier, the source said that one suicide bomber carried out the attack and put the toll at 15 killed and 30 wounded.

Violence and sporadic high-profile bomb attacks are still common in the Iraqi cities despite the dramatic decrease in violence since its peak in 2006 and 2007, when the country was engulfed in sectarian killings.