At least 17 people have been killed and 35 wounded in a car bomb attack in the Iraqi town of Tal Afar, close to the Syrian border.
It is reported that the bomb exploded in a pickup truck as it moved through a busy market.
In the past, the city has been the scene of fighting between insurgents and US forces, but US President George W Bush had held the city up as an example of progress in securing the country.
10 killed in series of attacks
Earlier, at least ten people were killed in continuing violence across Iraq.
Among those killed were two civilians in a roadside bomb attack in Baghdad against a patrol of FPS, a special security unit tasked with guarding ministry buildings and power stations.
Four members of the patrol were also wounded in the attack.
Separately a Sunni cleric, Raed Mohammed al-Dulaimi, was killed in southern Baghdad. The Iraqi Islamic Party said Mr Dulaimi was the 150th Sunni cleric to be killed in Iraq since 2003.
Gunmen shot dead a judge in western Baghdad, while another man was killed in Baghdad's notorious southern Al-Dura neighbourhood.
Two brothers were also shot and killed by gunmen in southern Baghdad.
In the northern city of Kirkuk, an Iraqi soldier was killed and two others wounded when their patrol was attacked by gunmen.
And a civilian and a political activist died after a shooting incident in the southern city of Amara.
12 bodies discovered in central Iraq
Meanwhile, police discovered the bodies of 12 men apparently killed in sectarian violence around Baghdad and central Iraq.
Three of the corpses, found beheaded, are believed to be those of Iraqi soldiers.
Their bodies washed up on the banks of the river Al-Malaeh, 60km south of the capital between the towns of Suwera and Hilla.
The three were kidnapped on Monday from Hilla where they had gone for training.