Baghdad: Iraq’s most revered Shiite cleric is calling for unity among the country’s forces battling the Daesh group after major Iran-backed Shiite militias pulled out of the offensive in the militant-held city of Tikrit in protest over US air strikes there.

Grand Ayatollah Ali Al Sistani’s spokesman, Ahmad Al Safi, said the top cleric’s message for Friday prayers was that such splits among Iraqi forces will have a negative impact.

According to Al Safi, Al Sistani said coordination between the military, Shiite militias and tribes is necessary for the success of the operation to retake Saddam Hussain’s hometown and defeat Daesh.

On Thursday, most of the Shiite militias announced their boycott of the Tikrit operation, after the US got involved and started providing air strikes in support of the mission at the request of Iraq’s government.