(IraqiNews.com) A website affiliated with the so-called Islamic State in Iraq and Syria (ISIS) confirmed the death of its leader, Abu Bakr al-Baghdadi.

The man was identified as Abu Huthaifa al Yamani but local media did not report any further details. Iraqi security officials have not confirmed the death.

The Pentagon said on Monday it could not corroborate reports that Baghdadi had been either killed or wounded in Iraq, acknowledging conflicting media reports from the region.

"We do not have any information to corroborate reports out of Iraq that Baghdadi has been either killed or wounded," Pentagon spokesman Colonel Steve Warren told reporters.

The reports came as US forces were deployed to Iraq's volatile western Anbar province for the first time in the fight against IS jihadists.

Fifty troops prepared the way for a larger contingent due to arrive in coming weeks, the Pentagon said on Monday.

"I can confirm that approximately 50 US military personnel are visiting Al-Asad Air Base to conduct a site survey of facilities for potential future use as an advise-and-assist operation location in support of Iraq security forces," Commander Elissa Smith said.

Meanwhile, the US and its allies launched a barrage of attacks against IS over the weekend, conducting 23 air strikes in Syria and 18 in Iraq.

Britain's Ministry of Defence said a remotely piloted Reaper aircraft successfully launched a missile attack on IS extremists near Baiji, north of Baghdad, where they were planting improvised explosive devices.

It is the first time Britain has used its unmanned aerial drones in Iraq to strike IS targets.

In Iraq, seven strikes hit near Baiji and others in or near Falluja, Mosul, al Qaim, Haditha, Ramadi and Rutba.

The Pentagon said Iraqi F-16 fighters would be sent to Arizona in December to improve the skills of Iraqi pilots currently training in the US.

"Iraqi pilots will begin flying Iraqi aircraft in Tucson in January," Pentagon spokesman Army Colonel Steve Warren said.

The US Air Force said 24 Iraqi pilots were in the F-16 training pipeline.

Iraqi government troops have ordered Shiite militias to stay back from the front lines to reduce hostility from villagers as they advance into Sunni areas held by IS fighters.

The Shiite militias played an important role halting the dramatic advance by IS fighters through northern Iraq in June when Iraq's army crumbled.

Since then, militias have received the endorsement of the Iraqi government but many Sunnis are angered by their presence and believe the militias have carried out killings and kidnappings with impunity.

Militia leader Major Saadi Hamdan said the order to move militia fighters away from the front had already paid off and improved cooperation with local villagers.

"Many people have started to call us and give us locations where terrorists are hiding and the places where they hide the car bombs," Major Hamdan said.

Abu Marwa, a farmer in the area, said many locals had embraced IS when the fighters initially arrived, because they promised to help defend the area from the militias and the Shiite-led Baghdad government.

"We were very pleased because we were living under the mercy of sectarian government forces. But those joyful feelings didn't last for too long," he said by telephone.

"Many people were executed by Islamic State because they were members of the police or army. More blood of the innocents was flowing now than under government troops."

Government forces, now supported by US-led air strikes, are advancing this week into the city of Baiji, held by IS fighters who have also besieged Iraq's biggest oil refinery nearby.

A victory in Baiji would be a psychological boost for the army after its collapse in the north in June.