By Saif Hameed and Ahmed Rasheed
BAGHDAD (Reuters) - Coalition and Iraqi planes struck a sprawling complex of palaces in the city of Tikrit on Thursday where Islamic State militants have been holding out for more than three weeks.
U.S.-led coalition planes launched their first air strikes against Islamic State targets in Saddam Hussein's home city on Wednesday, coming off the sidelines to aid Iraqi forces fighting alongside Iran-backed Shi'ite militia on the ground.
The decision to provide air support for the Tikrit campaign draws the United States into a messy battle that puts the coalition, however reluctantly, on the same side of a fight as Iranian-backed militia.
"The Iraqi air force with the coalition air force have conducted air strikes targeting the presidential palaces that are the headquarters of IS leaders and groups," Defense Ministry spokesman Brigadier Tahseen Ibrahim Sadiq said at an air base in Baghdad.
"This is the fourth sortie for the Iraqi air force since the early morning."
More than 20,000 Iraqi troops and allied Shi'ite paramilitary groups known as Hashid Shaabi have been taking part in the offensive since early March, but stalled around two weeks ago after sustaining heavy casualties.
Iraqi forces retook the area surrounding Tikrit in the first week of the campaign, and entered some districts of the city itself, which had been overrun in June by Islamic State.
IS COMMAND TARGETED
The militants have laid homemade bombs and booby traps in several areas including the presidential compound, which was built under Saddam and covers an area of around 6km overlooking the Tigris river, according to provincial officials.
The mayor of Tikrit said coalition and Iraqi planes were also striking the northern Qadisiya district, part of which is still held by insurgents, as well as the Shisheen neighborhood in the south.
"The focus is on the IS leadership command locations," said Omar al-Tikriti. Targets had to be carefully identified because IS fighters were believed to be holding prisoners in some of the 65 palaces.
"No ground offensive has started yet".
Two officers in the Tikrit operations center said coalition and Iraqi strikes had targeted parts of the complex used by the militants to store weapons and ammunition.
"We can see columns of black smoke rising from the site of the presidential palaces as a result of the air strikes," said local official Aref al-Dulaimi by phone near Tikrit.
The air strikes mark the first active participation by the U.S. military and Iranian advisors in the same battle space since last August when both were involved in breaking a siege of the Shi'ite Turkman town of Amerli by IS fighters.
Iraq's Defense Minister Khaled al-Obeidi played down the role of Iranian advisers and the degree of interaction between them and the coalition.
"The Iranian advisers have nothing to do with the work of the air force," Obeidi said. "The Iranians are working with the brothers in the Hashid Shaabi as advisers, and I think their presence is always in the rear positions."
The coalition joined the fray in Tikrit at the request of Iraqi military commanders, though Iranian-backed Shi'ite militia publicly rejected any U.S. role in the campaign to retake the jihadist bastion.