At least 22 people have been killed and 51 wounded in a quadruple car bombing in Karbala in central Iraq, near two of the holiest shrines in Shia Islam.

The four car bombs exploded on the periphery of a pedestrian-only area encircling the shrines of Imams Hussein and Abbas.

No group claimed responsibility, but the jihadist Islamist State has carried out a series of suicide bombings alongside its offensive throughout Iraq.

The attacks came as Prime Minister Haider al-Abadi met Grand Ayatollah Ali al-Sistani, Iraq’s top Shia cleric, in the holy city of Najaf. The discussion was a symbolic contrast to relations between Sistani and Abadi’s predecessor, Nuri Kamal al-Maliki, who did not meet for several years.

Abadi said at a news conference after his meeting with Sistani that the cleric spoke about “being more open to others, national unity, and chasing corruption and the corrupted as well as providing the best services to the Iraqi people”.

In Baghdad, a suicide bomber killed a guard to get into a small Shia mosque crowded with worshipers during midday prayer. He killed the imam and a worshiper, before detonating an explosives belt.

At least 18 people were slain and 33 wounded in the attack.