A suicide bomber has killed 14 people in the northern Iraqi city of Mosul. Reports say the attacker boarded a bus and then detonated a device.
The Iraqi government and US military believe that al-Qaeda militants have regrouped in Mosul, after being displaced from Baghdad and other areas.
In January a massive explosion at a apartment block in Mosul killed more than 60 people.
Insurgents were believed to be using the building to store munitions.
Iraqi and US forces have been reinforced in the city, 350km (240 miles) north of Baghdad, after a series of attacks, in one of which the police chief was killed.
Police in Mosul said the bus involved in Tuesday's blast was carrying passengers to Syria, Reuters has reported.
Also on Tuesday, near the city of Baquba, police said gunmen had seized 21 civilians from two minibuses.
The men were taken away after being stopped at a fake checkpoint.
Three women who had been on one of the minibuses were not taken.