Masked gunmen ambushed a bus carrying electoral officials in southern Iraq on Monday, killing two and seriously wounding a third, officials said. The attackers opened fire from a passing car in the Abu al-Khasib area south of Basra, which saw bitter infighting among Shi'ite factions before a US-backed Iraqi military operation curbed violence earlier this year. Two top members of a local committee preparing for provincial elections were killed, according to police and the head of Basra's elections panel, Hazim al-Rubaie. Upcoming elections are expected to redistribute power among Iraq's political and ethnic groups in what the US considers a necessary step toward reconciliation. But the date for the vote is uncertain because legislation has been stalled in the national parliament. Also Monday, mourners in Baghdad's Azamiyah district fired guns in the air to show their grief during the funeral of Farooq al-Obeidi, deputy head of a group of US-allied Sunni fighters who was killed by a suicide bomber. Nine other people were killed and at least 20 were wounded in Sunday night's blast, Iraqi officials said. They declined to be identified because they weren't authorized to release the information. The US military put the toll at eight killed, including six US-allied fighters, and 12 wounded. The bombing was significant because it occurred in the heart of the northern Baghdad neighborhood of Azamiyah, which has been surrounded by a concrete wall built by the US military to stop violence. That makes it difficult to smuggle explosives in from other parts of the city. The attacker had disguised himself in a black Islamic robe traditionally worn by women, officials and witnesses said. The bomber approached the checkpoint where council members were chatting, then detonated his explosives when a guard became suspicious and tried to push him away, according to a witness who spoke on condition of anonymity because of security concerns. Although Azamiyah was once a center of resistance to the US and its Shiite allies, many local Sunnis later abandoned the insurgency and joined the awakening council, which provides security there alongside Iraqi soldiers and police. Al-Qaida in Iraq has often targeted leaders of awakening councils. But Khalil Ibrahim, an aide to al-Obeidi, said the attack could have been carried out by rivals within the council itself. "We had received information that we would be targeted by groups within Azamiyah and within the awakening movement itself," he said, refusing to elaborate.