At least 26 people were killed and 24 others injured in an attack by two suicide bombers at a wedding in Iraq's Salahudin province, a security source said on Thursday.The attacks occurred on Wednesday night when two suicide bombers wearing explosive vests blew themselves up at the wedding party, the source told Xinhua news agency.A third suicide bomber tried to enter the scene of the two explosions, but he was killed after his explosive vest prematurely detonated, the source said, adding that many of the wounded were in critical condition.