At least 28 people have been killed in a suicide car bombing in a town north of Baghdad, police say.
The blast targeted a police station in the commercial district of the mainly Shia town of Dujail.
At least 40 others were injured in the explosion, which happened around 1800 (1500 GMT), police said.
The attack comes a day after the outgoing US troop commander in Iraq, General David Petraeus, said recent security gains were "not irreversible".
Violence in Iraq has declined steadily in recent months and is currently at a four-year low.
But attacks attributed to al-Qaeda-linked Sunni militants have continued in some provinces north of Baghdad.
Three weeks ago, 25 people were killed in Jalawla when a suicide bomber targeted a police recruiting centre.
According to police, the blast in Dujail took place just before dusk, when many people were on the streets getting ready to break their fast during the month of Ramadan.
A suicide bomber drove a vehicle filled with explosives at a police station, security officials said. A nearby medical clinic was also reportedly damaged.
The casualties included both police and civilians shopping at a nearby market, reports said.
Dujail, some 40 km (25 miles) north of the Iraqi capital, was the site of an assassination attempt against former leader Saddam Hussein in 1982.
He was executed in December 2006 after a court found him guilty of ordering the deaths of more than 140 Shias in response to the attack.