Two car bombs in different parts of the Iraqi capital Baghdad have killed at least 19 people, Iraqi police say.
About 45 people were wounded including government employees
The most deadly attack was a parked car bomb in a shopping area on the east bank of the Tigris, killing at least 15 people and wounding 45.
A suicide car bomber attacked a police headquarters in east Baghdad, killing four people, including two officers.
There is currently increased security in Baghdad because of a visit by Iranian President Mahmoud Ahmadinejad.
Iraqi police said the wounded in the first blast including employees of the nearby labour ministry and students from Baghdad university.
The attack on the police headquarters in the Maisaloon area wounded about 12 people. There was widespread damage to houses hit by the blast.
The authorities dismissed suggestions that the bombers had penetrated the stepped-up security operation for the first Iranian presidential trip for decades, which closed many roads in Baghdad.
"If the suicide bomber wants to commit suicide, how can we prevent them? It's not a violation of the tightened security measures," said Maj-Gen Qassim Moussawi.
US forces said they would not play a role in providing security for Mr Ahmadinejad, a major antagonist of Washington, unless asked for help.
Official government figures showed the number of Iraqi fatalities in violence in February were more than one-third higher than the previous month, reversing six months of falling death tolls.
Figures released by Iraq's interior, defence and health ministries said 633 civilians died violently in February, compared with 466 in January.
A previous drop in violence was attributed to a surge in US troop numbers, the formation of anti-Qaeda militias by Sunni Arab tribes and a freeze in activities of the Mehdi Army militia loyal to radical Shia cleric Moqtada Sadr.
Separately in the southern city of Basra, gunmen ambushed a top provincial police chief, killing him and three bodyguards.
Colonel Qassim Obeid had recently been transferred from Basra to the central province of Dhi Qar, police said.
North of Baghdad, the US military found the bodies of 14 men with their hands tied behind their backs and shot in the head in a mass grave, believed to have been the work of al-Qaeda.