By Maggie Fick
BAGHDAD, March 16 (Reuters) - Iraq said on Monday it had put its Tikrit offensive on hold and senior officials called for more air strikes to dislodge Islamic State militants who have laid explosives across Saddam Hussein's home city and still hold its central districts.
The offensive, the largest yet against insurgents who swept through northern Iraq in June, has been stalled for four days after Iraqi security forces and mainly Shi'ite militia pushed into Tikrit last week.
They have struggled to gain further ground against the militants who are holed up in a vast complex of palaces built when Saddam was in power.
Military officials in Tikrit said there was no fighting on Monday in the city that was home to more than 250,000 people before it was overrun last year.
Government forces are in control of most of the northern Qadisiya district as well as the southern and western outskirts of the city, trapping the militants in an area bounded by the river that runs through Tikrit. Though Iraqi forces and allied militiamen may have the insurgents in a chokehold, officials are increasingly citing air power as necessary to drive out the remaining insurgents.
"We need air support from any force that can work with us against IS," Deputy Minister of Defense Ibrahim al-Lami told Reuters, declining to say whether he meant from the U.S.-led coalition or Iran, which is playing a role in the assault.
The U.S.-led coalition has been conspicuously absent from the offensive, the biggest to be undertaken by Iraqi forces since Islamic State seized around a third of the country last summer including Tikrit.
Interior Minister Mohammed al-Ghaban said authorities had put a temporary halt to the offensive in Tikrit, capital of the mainly Sunni Muslim Salahuddin province.
"We have decided to halt military operations in Salahuddin in order to reduce casualties among our heroic forces... and to preserve the remaining infrastructure," the minister said at a news conference in the city of Samarra, 95 kilometers (60 miles) north of Baghdad.
"The situation is under control and we will choose the appropriate time to attack the enemy and liberate the area."
More than 20,000 troops and Iranian-backed Shi'ite militia are taking part in the operation, which began two weeks ago, supported by a relatively small contingent of Sunni fighters from Tikrit and the surrounding Salahuddin province.
The assault is seen as a litmus test for any future attempt to retake the large northern city of Mosul, which is likely to be a far more complex operation.
Meanwhile, coalition air strikes helped Kurdish forces seize the villages of Wahda, Saada, and Khalid from Islamic State in the north - part of a broader week-long offensive to drive the militants away from the oil-rich city of Kirkuk.
Shi'ite Turkmen fighters also clashed for a fourth day with Islamic State insurgents near the village of Bashir, south of Kirkuk.
In Baghdad, Special U.S. presidential envoy General John Allen addressed a meeting of Iraqi and foreign officials aimed at kicking off efforts to stabilize and rebuild territories retaken from Islamic State.
The militants have been driven back by Kurdish peshmerga forces in the north, and Shi'ite militia known as Hashid Shaabi (Popular Mobilization) in the eastern province of Diyala, the Baghdad belt and north of the capital.
Allen said Iraqis were beginning to recover from life under Islamic State in Diyala and "hopefully soon" in Tikrit, but that local governance would prove difficult because many officials had been killed, were in exile, or co-operated with Islamic State.
The Prime Minister's spokesman Rafid al-Jaboori echoed calls for more air strikes: "We have been saying we need more air support for all operations," he told Reuters. "We welcome air support for all our campaigns against IS."
Asked by Reuters for his response to the Iraqi appeals, Allen said it would not be appropriate for him to comment. (Additional reporting by Ahmed Rasheed and Saif Hameed in Baghdad, Mustafa Mahmoud in Kirkuk; Writing by Isabel Coles; Editing by Dominic Evans)