The aftermath of the bomb in north-west Baghdad
At least 14 people have been killed in Baghdad on the first day of voting in Iraq's parliamentary elections.
Suicide bombers attacked two polling stations in different areas of the city killing at least seven people and wounding many others.
Earlier in the day, a mortar attack on a crowded market killed seven and wounded at least 10 people.
The poll is seen as a security test for Iraq as the US prepares to reduce its military presence in the coming months.
The early voting involves hundreds of thousands of government employees, the sick and prisoners.
The first suicide bomber attacked a polling station in the Mansur district of Baghdad. Three soldiers were killed and 15 wounded.
A little under an hour later another suicide bomber blew himself up in central Baghdad, killing at least four and wounding 10 others.
There were conflicting reports about the first attack of the day in north-western Baghdad.
Agence France-Presse news agency reported that a mortar had been fired at a polling station, but hit a crowded market. Seven people, four of them children, were killed and 23 wounded.
Other reports said the blast was caused by a roadside booby-trap or a rocket fired near a school due to be used as a polling station on Sunday.
On Wednesday, three suicide bombers attacked police and a hospital in Baquba, killing at least 30 people.
Insurgents have threatened to disrupt the elections - regarded as an important test of Iraq's efforts to achieve sovereignty and overcome sectarian divisions.
"Terrorists wanted to hamper the elections, thus they started to blow themselves up in the streets," said Deputy Interior Minister Ayden Khalid Qader said.
The majority of the country goes to the polls on Sunday. More than 6,000 candidates are competing for 325 seats in the election.
The alliance led by current Prime Minister Nouri Maliki has claimed credit for a sharp fall in violence between Shia and Sunni militants.
Mr Maliki is being challenged by a number of groups, including a Shia coalition that includes radical cleric Muqtada al-Sadr and ex-PM Iyad Allawi's secular cross-sectarian alliance.
Travel around the country has been restricted and the authorities have cancelled all leave for security services.
On polling day itself, more than 200,000 security personnel will be on duty in Baghdad.
The US is planning to reduce its military presence by about half in the coming months and withdraw completely from Iraq by 2011.