Iraqi government troops backed by Shi'ite militia have driven out Islamic State (IS) militants from a key oil refinery north of Baghdad in a wide-scale military operation, authorities say.
The Joint Military Command said on October 16 that the forces retook Baiji refinery, Iraq's largest, and the nearby town of Siniya.
After retaking the refinery north of the city, security forces were sweeping the sprawling complex for bombs and any remaining IS fighters.
At least 15 IS militants and six anti-IS fighters were killed in the battle to retake the refinery, officials said.
The Iraqi forces' next goal is to recapture the nearby town of Baiji.
Baiji, about 250 kilometers north of Baghdad, fell to IS during its blitz across northern Iraq a year ago, but the refinery facility had remained contested. The town is strategically significant as it lies on the road to IS-held Mosul, Iraq's second-largest city.
"Iraqi forces are moving deep into Baiji; they have retaken the industrial area and several other neighborhoods," an army colonel told AFP.
"We control about 60 percent of the city; there are not so many [IS] fighters left and they are trapped," he said.
The capture of the Baiji refinery is significant because IS, which has declared an Islamic caliphate in the territories it controls in Syria and Iraq, has used sales of smuggled oil to finance much of its operations.
Still, the refinery, which once produced 300,000 barrels per day of refined products and met half of Iraq's needs, is feared to have been damaged beyond repair.
The military operation -- dubbed Labeik ya Rasool Allah, or "At your command, messenger of God" -- was launched on October 12 as the second phase of a large-scale operation to drive IS out of Salah al-Din Province in central Iraq.
The government troops were backed by paramilitary forces, made up mainly of Shi'ite militias.
The leader of the Iranian-backed paramilitary group Asaib Ahl al-Haq, Sheikh Qais al-Khazali, was filmed in a military uniform accompanying troops inside the refinery in a video released by the group's TV channel, Al-Ahad.
The footage showed the troops walking through the wreckage of the refinery complex as black smoke billowed from different areas. The troops waved Iraqi and Shi'ite militia flags.
Hadi al-Ameri, the most visible commander of the Hashed and a leading member of the Tehran-backed Shi'ite Badr militia, has been omnipresent on the Baiji front lines.
Qassem Soleimani, commander of the foreign wing of Iran's elite Revolutionary Guards, was also reported in Iraqi media to have played a key role.
The U.S.-led coalition against IS, which is more active on the Anbar front, said it had carried out two strikes in the Baiji area.
It also said it had destroyed parts of another refinery, in Qayyarah, between Baiji and Mosul, that "was used by [IS] to produce oil for the black market to fund their terrorist activities."
Iraqi forces were also pressing an offensive to retake Ramadi, which IS seized in May, with the backing of coalition air strikes.
Coalition warplanes have carried out at least 69 strikes against IS in the Ramadi area this month alone.
Major ground advances in recent days have allowed pro-government forces to almost completely encircle Ramadi, where the coalition estimates the number of remaining IS fighters to be between 600 and 1,000.
"We're encouraged by this progress, but much fighting lies ahead. Important for Iraq forces to keep moving forward," U.S. military spokesman Patrick Ryder said on social media.
Iraqi forces were also tightening the noose around IS in the town of Baghdadi, further west up the Euphrates River in Anbar Province.
Army Major General Ali Dabbun said his forces, with backing from local Sunni tribal fighters, had made good progress in Baghdadi.
"Our forces defused 62 IEDs [improvised explosive devices], blew up three rigged buildings, causing no victims," he said.
With reporting by AP and AFP