At least 22 people have been killed after a series of suicide attacks hit Shia mosques in Iraq's northeast, officials have said.

In the town of Balad Ruz, a suicide car bomber attacked the al-Zahraa mosque as worshippers were leaving after the Friday mid-day prayers, a police officer said.

A second suicide bomber on foot then attacked the crowds gathered in the aftermath.

The twin attacks in Balad Ruz, located about 70km northeast of Baghdad, killed at least 18 people and injured at least 41.

Among the dead were the leader of the town's police commandos, Adnan Mohammed al-Timimi, and two policemen, the official added.

The Interior Ministry blamed fighters from the Islamic State of Iraq and the Levant (ISIL) armed group for the attacks.

In another incident, a suicide bomber drove his car into worshippers as they were leaving the Imam Hussein Shia mosque in the town of Kanaan, about 75 kilometres northeast of the Iraqi capital, the police officer added.

Four people were killed and at least 18 wounded in that attack.

Two medical officials confirmed the casuality figures to the Associated Press news agency.

The predominantly Shia towns are located in Iraq's religiously-mixed province of Diyala, which has witnessed major clashes between government forces and Sunni fighters in recent months.

Friday's bombings came ahead of next week's major Shia event commemorating the anniversary of the 8th century death of a religious figure, Imam Mousa al-Kazim, when thousands of pilgrims march to his shrine in northern Baghdad.

According to the UN figures, some 2.7 million people have been displaced inside Iraq due to the fighting, including 110,000 who fled from renewed fighting in and around the city of Ramadi in the western Anbar province in last month.

The bombings occurred outside a Shia place of worship in eastern Iraq as they filed out after Friday prayers, police and hospital sources said [Reuters]

Source: Associated Press