A suicide car bomber has killed at least 11 people and injured about 30 others in Baghdad, Iraqi officials say.
Hospitals in Baghdad see a daily stream of injured civilians
They say the attacker rammed his vehicle into a police checkpoint near Baghdad University in the south-western Jadiriya district of the capital.
Reports said police officers and students were among the victims.
Separately, one report said a number of blasts were heard in Baghdad, some in the heavily-fortified Green Zone where the Iraqi parliament is located.
A Pentagon report earlier this week said attacks on US and Iraqi troops and civilians had reached their highest level since power was handed over to an interim Iraqi government in June 2004.
It said the number of attacks had risen to almost 1,000 a week in recent months.
The worst violence had been in Baghdad and the western province of Anbar, long the focus of activity by Sunni insurgents, the report said.