Iranian forces quit Tikrit battle as US fills vacuum

Iran has pulled its forces out of the operation to take Tikrit from the Islamic State group, a source has told al-Araby al-Jadeed, as the Iraqi government called in US air support for the first time to aid its faltering campaign.

An unnamed source close to Iraq's Shia Popular Mobilisation Forces militia told al-Araby on Friday that the Iranian Revolutionary Guard general, Qasem Soleimani, "withdrew from Tikrit five days ago".

That withdrawal came after the Shia militias "resigned" from the battle, which was launched with much fanfare by the Iraqi government but which has dragged on for weeks. 

Iran has not commented officially on its position in Tikrit. However, the militia source told al-Araby that Iran withdrew came after the militia "resignation" and due to their inability to break Tikrit, which led to Iraq's government calling for US support earlier this week.

In a statement on Thursday, the US Central Command's Lloyd Austin said that the Shia militias had left the area around Tikrit before US forces provided air support.

Iraqi security expert Ahmad al-Saeidi told al-Araby al-Jadeed that Iraq's prime minister Haider al-Abadi "had prior knowledge of the Iranian withdrawal", which forced him to "submit a request to Washington for airstrikes."

Despite the aparent loss of Iranian support, Iraqi troops pressed thier offensive in Tikrit on Friday as fighter planes pounded IS targets from above, a day after Abadi declared victory was "near" for his forces. 

However, a senior military commander told the AP news agency that roadside bombs and booby traps planted by Islamic State fighters demanded extreme caution.

US began airstrikes on Tikrit late Wednesday. The battle for Tikrit is seen as a key step toward eventually driving the Islamic State group from Iraq's second largest city Mosul, which is further north.