OUR ALLIES ON THE MARCH:

In their biggest offensive against "Islamic State" (IS) fighters so far, Iraqi government forces and Iran-backed militia have entered the town of al-Dour on Tikrit's outskirts.

Al-Dour is where executed former Iraqi dictator Saddam Hussein was found hiding in 2003. Tikrit was his home city.

Hadi al-Amiri, leader of the largest Shiite militia group taking part in the operation, said al-Dour had been "totally liberated" and that the advance on al-Alam, another key town north of Tikrit, would take place on Saturday.

The Iraqi army, joined by thousands of Shiite militiamen backed and advised by Iran, is five days into the advance on Tikrit 140 km (80 miles) northwest of the Iraqi capital, Baghdad, on the Tigris River.

Army officials said on Friday that they had captured a farm to the east of Tikrit that belonged to Saddam's deputy Ezzat Ibrahim al-Douri. He is now a prominent ally of the jihadist fighters. He is also the only member of the former regime still at large following the 2003 US led invasion of Iraq.

If the offensive is successful, it could leave Iranian forces and their Shiite allies in control of the Syrian side of the Golan. And from that vantage point, Tehran could gain an additional means of deterrence against Israel in the remaining months before the June 30 deadline for negotiations over Iran's nuclear program.

"The Iranians through Hezbollah really do wish to complete this encirclement from the north [of Israel] now that they have access to the Golan.... I think that is a key strategic move for them," says Phillip Smyth, a researcher at the University of Maryland and author of the Hizballah Cavalcade blog, which focuses on Shiite militarism in the Middle East.

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