A car bomb and a suicide bomber killed at least nine people and wounded 54 in northern Iraq on Saturday, police and medical sources said, in the latest of a wave of attacks in crowded public places.
The bombings took place in the town of Tuz Khurmato, 170 km (100 miles) north of the capital Baghdad, in a region which both the central government and autonomous Iraqi Kurdistan claim as theirs.
The first bomb detonated in a car in a busy market near a Shi'ite mosque after prayers and was quickly followed by a suicide bomber wearing an explosive vest, the sources said.
Iraqi authorities are struggling with the worst violence in at least five years and say Sunni Muslim insurgents linked to al Qaeda are to blame for most of the attacks, which have killed hundreds each month since the beginning of 2013.
Since U.S. troops withdrew at the end of 2011, attackers have been increasingly targeting markets, cafes and sports events, rather than just army checkpoints and police patrols.
The victims have mainly been civilians in Shi'ite areas.
Iraq's sectarian balance has come under pressure from a prolonged political stalemate at home and the civil war in neighboring Syria, where mainly Sunni rebels are fighting to topple a leader backed by Shi'ite Iran.
So far Iraqi Shi'ite militias, most of which disarmed in recent years and joined the reconstituted security forces or entered the political process, have largely held their fire.
But a worsening Sunni insurgency could prompt Shi'ite militia to again take up arms to defend themselves.
This has fuelled fears that Iraq could slide into the kind of sectarian violence of 2006-2007, when tens of thousands were killed.
In a sign of growing frustration in the Sunni community, some Sunni Muslim mosques closed in Baghdad on Saturday in a rare protest at recent attacks on worshippers. It was not clear how many mosques in Baghdad had shut down and some in the center of the city remained open.
A council of senior clerics said last week that all Sunni mosques in the capital should be shut in protest at the security situation.
They said Iraq's security services had not done enough to protect their communities.
Two roadside bombs went off near Sunni mosques in the southern and western outskirts of Baghdad after prayers on Friday, killing three worshippers and wounding 12, the police said.
No one has claimed responsibility for the attacks but the clerics say there is sustained a campaign against Sunni worshippers and imams.