At least two people have been killed in a suspected car bomb blast outside a police station in Iraq.
Several people were killed in a blast in Baquba last week
A number of people were injured in the explosion in the central town of Baquba, witnesses said.
It comes less than a week after at least six people were killed in a blast outside a mosque in the same town.
Hours before the latest blast, US forces in Iraq detained four relatives of former vice-president Izzat Ibrahim al-Douri, the military said.
Thrown to ground
A police officer at the scene of the blast said a car sped towards the police station moments before the explosion.
"A car exploded in front of the building of the civil emergency police unit killing and injuring many," said Haidar Ismail.
"I saw the remains of the car driver all over the place and the building was severely damaged."
Witnesses said the force of the blast threw scores of people to the ground.
Iraqi hospital sources said two civilians were killed and about 30 people, including 14 police officers, were hurt.
The BBC's Alastair Leithead in Baghdad says the blast seems to be another attack aimed at destabilising the new Iraqi police force which has been assembled by the US-led coalition.
There has been a spate of attack on Iraqi police stations in recent months.
Baquba, a largely Sunni Muslim town, lies close to the so-called "Sunni triangle", where support for former Iraqi leader Saddam Hussein remains strong.
'One step closer'
Ibrahim al-Douri is considered by many to have been the deposed Iraqi leader's right-hand man and is the most senior member of Iraq's former regime still at large.
The relatives, all male, were detained in a raid on two homes in the central city of Samarra, officials said.
Douri: Seen as ex-president's right-hand man
US forces have offered a $10m reward for the capture of Mr Douri, who they suspect of masterminding many attacks on coalition forces.
US Lieutenant Colonel David Poirier said the men arrested had been "enablers" for Mr Douri and they had good information on his whereabouts.
"We think that [the raid] brought us one step closer to finding him," he told Reuters.