Iraq on Thursday executed 12 Al-Qaeda members convicted for the massacre of 70 people at a wedding, although they were officially put to death for other murders, the deputy justice minister said.

The 12 were executed for the murders of cooking gas salesmen, though they were also convicted of involvement in the 2006 wedding massacre, Busho Ibrahim told AFP.

Fifteen people were convicted of the crimes, but "three of them were not executed today because we still have legal procedures to deal with," the minister said.

Firas Fleih al-Jaburi, who was said to be the leader of a cell involved in a string of attacks, was among those executed, Ibrahim added.

Security forces claimed he posed as a human rights activist who fought to improve prison conditions in a bid to elude capture.

Abdelsattar Birakdar, the spokesman for the Supreme Judicial Council, had said earlier on Thursday that 16 people were executed.

Baghdad security spokesman Major General Qassim Atta said in May that "the gas sellers were from Sadr City in Baghdad. They used to come to the Taji area to sell gas to residents."

The Sadr City district in the north of the capital is overwhelmingly Shiite. Taji on the city outskirts is mainly Sunni Arab.

The gas sellers were killed in 2006 and their bodies set on fire, Atta said without specifying how many.

According to police, militants also carried out the systematic killing of a wedding party celebrating the marriage of a Shiite man to a Sunni woman in the Taji area in 2006.

The murders came as confessional violence was raging across Iraq, with tens of thousands killed in 2006 and 2007.