At least 13 people were killed on Saturday in two separate bombings in northern Iraq while they were fleeing from a town held by the Islamic State extremist militia, police said.
Eleven civilians, including children and women, were killed when a suicide bomber blew himself up amid a crowd of people who had escaped from the Islamic State-ruled town of Sharqat, around 280 kilometres north of Baghdad, a security official said.
Nine others were injured.
The victims were heading to nearby security forces when the bomber detonated his vest in their midst, the official added on condition of anonymity.
There was no immediate claim of responsibility for the attack.
In a second incident, two children were killed and 10 injured when a bomb, believed to have been planted by Islamic State, went off outside Sharqat.
Government forces are imposing a tight siege on Sharqat ahead of an expected attack to dislodge Islamic State from the town.
The blockade has resulted in shortages of food and medical supplies, and prompted an exodus from the town.
Last month, Iraq announced retaking full control of the western city of Fallujah from Islamic State as part of a sustained US-backed campaign against the group.
The Iraqi army has started digging a trench around Fallujah as part of a security plan aimed at preventing Islamic State from attempting to recapture the city, sources at the Defence Ministry said on Saturday.
The trench will be about 12 kilometres long, 2.5 metres deep and 12 metres wide, they added.
An opening will be set up to facilitate residents' movement into and out of the city, the sources said.
Islamic State seized territory in northern and western Iraq in a blitz attack in mid-2014.
In recent months, the radical group has suffered major military setbacks and lost ground in the country.
The group still controls Mosul, Iraq's second-largest city.