BAGHDAD (AP) — 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 (360 kilometers) 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 (80 kilometers) 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.

Elsewhere, a roadside bomb exploded on a police patrol in Muqdadiyah, 60 miles (90 kilometers) north of Baghdad. Three policemen were killed and two were wounded in that blast, the officials said.

Medics confirmed the casualty figures. All officials spoke on condition of anonymity because they were not authorized to talk to the media.

Violence has ebbed in Iraq, but insurgents frequently attack security forces and Shiites in an attempt to undermine the government's authority.