A string of insurgent attacks, including a car bomb targeting a Shiite mosque, killed 10 people in Iraq on Friday, officials said.

The strikes highlight the challenges still facing Iraq's Shiite-led government as it struggles to maintain security over the country.

The car bomb struck a Shiite mosque as worshippers were performing Friday prayers in a village near the former al-Qaida stronghold of Mosul, a city 225 miles northwest of Baghdad. Three people were killed and 35 wounded in that attack, police officials said.

Hours earlier, gunmen opened fire on a group of so-called Sahwa fighters manning a checkpoint near the town of Dujail, 50 miles north of the Iraqi capital.

The Sahwa are Sunni Arabs who joined forces with the U.S. military to fight al-Qaida's Iraq branch at the height of the country's insurgency. They have since been regularly targeted by Sunni insurgents who seem them as traitors.