Iraqi military forces reached the center of the northern city of Baiji on Sunday in an effort to break an Islamic State in Iraq and the Levant (ISIL) siege on the country's biggest oil refinery, triggering fierce clashes with the insurgents, according to an army colonel and a witness.
ISIL insurgents seized Baiji in June during a lightning advance through northern Iraq. Since then, they have surrounded the refinery and halted its production while a detachment of government troops has held out for months under siege inside it.
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 neighborhood and city center.
ISIL had placed bombs along roads in Baiji and deployed snipers to keep government forces from advancing, tactics used in other cities held by the Al-Qaeda-breakaway group, which controls swathes of both Iraq and Syria.
"There are IEDs (improvised explosive devices) and snipers that are slowing down the advance, but the presence of the air force has facilitated the process of dismantling the IEDs in order to push forward," said the colonel.
"The areas taken so far are 3 miles away from Baiji's refinery," he added. He said 12 insurgents had been killed.
Baiji resident Sultan al-Janabi told Reuters by telephone from his home that clashes had been raging since the advance, the first time security forces reached the city center since launching a new encirclement strategy at the end of October.
"Violent confrontations are taking place in Baiji right now. I've been hearing continuous fire and loud bangs," said Janabi.
The Baiji oil refinery is strategically important to ISIL, which Iraqi oil industry officials estimate is making multi-million dollar profits from the illegal trade.
Late last month, Iraqi government forces tried a new approach. Backed by Shia militias and helicopter gunships, they circled Baiji from the west in order to retake the city and cut off supply lines to the Sunni insurgents surrounding the refinery a few miles away.
Government forces, including counter-terrorism units, trapped inside the compound have been surviving on airdrops as military forces outside try to drive ISIL fighters away.
Al Jazeera and Reuters