Iraqi military forces reached the centre of the northern city of Baiji on Sunday in an effort to break an Islamic State siege of the country's biggest refinery, triggering fierce clashes with the militants, according to an army colonel and a witness.
Separately, contradictory reports emerged over the fate of Islamic State leader Abu Bakr al-Baghdadi after U.S.-led air strikes against the group in at least two locations in Iraq on Friday night.
The United States said it had no information to indicate Baghdadi had been hit. State television cited reports that Baghdadi had been wounded. It gave no further details.
Baghdadi's fighters seized much of northern Iraq five months ago in a lightning offensive which also saw them capture the city of Baiji and surround its oil refinery, halting production and besieging a detachment of government troops there.
The colonel said Iraqi troops entered Baiji, a city of about 200,000 people, from the south and west and took over the al-Tamim neighbourhood and city centre.
Islamic State had placed bombs along roads in Baiji and deployed snipers to keep government forces from advancing, tactics used in other cities held by the ultra-hardline Sunni group, which controls swathes of both Iraq and Syria.
"The areas taken so far are 6 km (4 miles) away from Baiji's refinery," the colonel said, adding 12 militants had been killed.
Baiji resident Sultan al-Janabi told Reuters by telephone from his house that clashes had been raging since the advance, the first time security forces reached the city centre since launching a new encirclement strategy at the end of last month.
BAGHDADI'S FATE UNCLEAR
Major Curtis Kellogg, spokesman at the U.S. military's Central Command, said it had no information to corroborate press reports that Baghdadi was wounded in any strike on the city of Mosul in the north and al-Qaim to the west.
"We cannot confirm that Baghdadi was present when we struck the convoy near Mosul on Friday night," he said.
"We conducted two airstrikes near Al Qaim Friday evening destroying an ISIL armoured vehicle and two ISIL checkpoints but we're not aware of another gathering of ISIL leaders in Al Qaim."
ISIL is the acronym of another name for Islamic State.
A Twitter account claimed Baghdadi had been wounded but other accounts that support Islamic State said the report was untrue.
A member of western Anbar Province's security committee said he had heard unconfirmed reports that Baghdadi had been wounded and moved to Syria. Several other Anbar officials gave contradictory reports on Baghdadi's fate.
Even if Baghdadi were killed, Iraq would still face the challenge of defeating a group which quickly defeated its military in the north in June and is determined to expand a self-proclaimed caliphate.
The United States, which fought Islamic State's predecessor al Qaeda during the American occupation of Iraq, will send up to 1,500 more troops to train Iraqi forces. Britain also plans to send trainers.
U.S. air strikes, launched after Islamic State beheaded Western hostages, have slowed down the Sunni insurgents and enabled Iraqi security forces to make some gains.
POLICE GENERAL KILLED
On Friday night, a suicide bomber rammed a truck packed with explosives into a Humvee transporting senior police commander General Faisal Malik, one of the supervisors of the campaign against Islamic State militants surrounding the refinery. The general and two policemen were killed.
The truck used in the attack was armoured, the army colonel and a provincial police command centre said, suggesting Islamic State had seized it from defeated Iraqi troops. Tanks and anti-aircraft weapons have also been taken.
The army colonel estimated that Iraqi forces had taken about 40 percent of the city centre. That could not be independently confirmed.
Iraqi security forces have used helicopters to attack Islamic State insurgents surrounding the refinery.
But months of operations have failed to rescue comrades trapped inside and ensure the strategic site will not fall into the hands of Islamic State, who have used oil and fuel to fund their self-proclaimed caliphate.
Iraqi oil industry officials estimate Islamic State is making multimillion-dollar profits from the illegal trade.
Government forces, including counter-terrorism units, inside the compound have been surviving on airdrops as military forces outside tried to drive Islamic State militants away.
The Baiji refinery was producing around 175,000 barrels per day before it was closed, a senior Iraqi official said in June. Iraq's domestic daily consumption is estimated at 600,000-700,000 bpd.