Seven people have been killed and others injured after two separate attacks in Iraq.
Police said a bomb left by the side of the road at the Omar mosque in west Baghdad killed four people and injured 11 others as they were walking away after Friday prayers.
Meanwhile, police said that three policemen were killed when gunmen attacked a security checkpoint in the city of Fallujah, a former al-Qaida stronghold 65 kilometers (40 miles) west of Baghdad. Two other policemen were hurt in the attack.
Health workers confirmed the casualties.
In a show of national unity, Shiite and Sunni worshippers held joint prayers on Friday in a Shiite mosque in downtown Baghdad amid tight security measures.
Sunni cleric Khalid al-Mulla urged the government and the Iraqi people to stop the bloodshed by uniting against "the terrorists who want to kill our sons in the name of Islam".
He said: "The blood that is being shed is precious Iraqi blood ... so we should say 'Enough' to these killings."