A suicide bomber has blown himself up at a lunch hosted by a Sunni candidate in Iraq's upcoming regional elections, killing 20 people.
The blast ripped through a hospitality tent pitched next to the house of Muthana al-Jourani, who is running for the provincial council and held the lunch rally for supporters, spokesman Sadiq al-Huseini said.
The attack took place in Baqouba, a mixed Sunni-Shiite city 35 miles north-east of Baghdad.
Insurgent and sectarian attacks have been rampant there in the decade since the 2003 US-led invasion. Violence is expected to surge in the run up to Iraq's provincial elections on April 20.
The police officer said al-Jourani, who was injured in the attack, had not requested any extra security for the political event.
In the city's morgue, at least 10 bodies could be seen covered in black plastic sheets.
Eyewitness Ahmad al-Hadlouj, a 34-year-old who was wounded in the blast, said hundreds of people had gathered in the side street for the rally. His father, a member of the candidate's political bloc, was also wounded.
"This is our blood (shed) for the people," said Mr al-Hadlouj. "We will still participate in elections."
There was no immediate claim of responsibility, but the police officer said the attack was the hallmark of al Qaida militants who have used suicide bombers, car bombings and coordinated attacks to try to destabilise the country and undermine confidence in the Shiite-led government. Hard-line Sunni extremists see Shiites and those who work with them as heretics.
A wave of deadly bombings and attacks in March prompted Iraqi officials to conclude that al Qaida's Iraqi branch, known as the Islamic State of Iraq, has been getting stronger. They say rising lawlessness on the Syria-Iraq frontier and cross-border co-operation with the Syrian militant group Nusra Front has improved the militants' supply of weapons and foreign fighters.