BAGHDAD (AFP) - Early voting in Iraqs general election was vershadowed Thursday by two suicide bombings at polling stations that killed seven soldiers and a mortar attack that claimed the lives of seven civilians. The blasts, which also wounded 48 people, including 25 Iraqi soldiers, came despite a massive security operation, with troops, prisoners and the sick casting their ballots in special voting ahead of Sundays parliamentary ballot. The leader of Al-Qaeda in Iraq, Abu Omar al-Baghdadi, threatened last month to disrupt the election by military means and 200,000 police and soldiers have been deployed in the capital alone to try to prevent attacks. The first suicide bomber blew himself up at a school being used as a polling centre in the upscale west Baghdad neighbourhood of Mansur. Three soldiers were killed and 15 wounded. Forty-five minutes later, a bomber detonated his explosives-laden vest in another school-turned-polling station in Baab al-Muadham, in the centre of the city, killing four soldiers and wounding 10. Earlier, seven people, four of them children, were killed and 23 wounded in an attack in northern Baghdad near a polling station that will be used in Sundays election, a medical official said. An AFP correspondent at the scene said the deaths appeared to have been caused by a mortar round which hit a building housing shops and apartments. The roof of the building caved in killing those below and leaving a scene of devastation with blood and scattered childrens clothes on the ground. I was speaking with my son and he was on the roof to fix the generator cable when the building was partly destroyed by a mortar, said Abu Nabil whose shop was across the street from the building hit. By chance, nothing happened to him, but I cannot hear. The bloodshed came even as Syrian President Bashar al-Assad, whose country has been accused by Baghdad in the past of harbouring Iraqi insurgents, expressed hopes for a calm election. The US military sees the poll as a crucial precursor to a withdrawal of combat troops in August and said it would continue to provide Iraqi security forces with intelligence, logistical and air support for the election. Around 950,000 people unable to vote on Sunday were expected to take part in Thursdays early voting for the second national ballot since dictator Saddam Husseins ouster in the US-led invasion of 2003. Nidhal, a nurse at Baghdads Abid al-Haitham hospital, said she had voted for a secular candidate. Sundays vote will usher in a government tasked with tackling still high levels of violence, endemic corruption and an economy in tatters. Sunni Arabs were expected to turn out in force to cast their ballots, in stark contrast to the last general election in 2005 which they mostly boycotted in protest at the rise to power of the nations long-oppressed Shia majority. That boycott deepened the sectarian divide and heightened violence that killed tens of thousands of Iraqis and which has only eased in the past two years. A Shia is almost certain to take the top job of prime minister. Shias were united in the 2005 polls but this time round are divided, a development hailed by some as a move away from rigid sectarian politics. Prime Minister Nuri al-Maliki, the Shia head of the State of Law Alliance, a religious coalition with a secular outlook that includes Sunni tribal sheikhs, has said he was certain of victory. His rivals include former premier Iyad Allawi, who heads the Iraqiya list, a secular coalition which has strong support in Sunni areas. Also seeking the top job are Ahmed Chalabi, a former deputy premier once favoured but now loathed by Washington; Adel Abdel Mahdi, the countrys Shia vice president, and finance minister Baqer Jaber Solagh. Under the Iraqi electoral system no one party will emerge with the 163 seats needed to form a government on its own and the ensuing horse-trading to form a governing coalition could be protracted. Campaigning in the weeks leading up to the vote has been dominated by a bitter feud over who can stand in the election. Around 500 candidates, both Sunni and Shia, were excluded from the poll after being accused of links to Saddams outlawed Baath party.