The Islamic State (IS) militant group on Saturday launched a series of suicide attacks on Iraq's largest oil refinery, a senior army officer said.
The group claimed it broke into the Baiji oil refinery but the Iraqi army said the site, which has been the scene of fierce battles since the IS swept across the region last year, remained under its control, France24 said in a report.
"Today IS launched an attack against the Baiji oil refinery," said a major general from Salaheddin Province, in which Baiji is located. He described the attack on the refinery, which lies around 200km north of Baghdad, as "the fiercest since we broke the siege a few months ago."
He said IS militants attacked the large complex from three fronts: Al-Bujwari village to the south, the housing compound for refinery employees to the west and one of the smaller plants producing derivatives to the east.
The Iraqi forces protecting the refinery regained control of the entrances and that the entire site is now under government control, he noted.
The IS released pictures showing convoys of their Humvees attacking the refinery perimeter and of fighters apparently inside the limits of the site.
The army officer said 20 IS insurgents were killed in raids by the Iraqi air force, although that figure could not be verified.
"Daesh is trying to send the message that they are everywhere, but in fact they are defeated and cannot advance," he said.
It launched a massive offensive on northwestern Iraq in June. Counter-terrorism and other forces tasked with protecting the vital refinery held out and remained besieged for months.
An Iraqi operation, backed by airstrikes from a US-led coalition, eventually broke the siege in October and retook the city, which lies just south of the refinery. The militants have since recaptured the city.
Following their victory in Tikrit earlier this month, government forces will have to retake it as they continue to move north towards the main IS hub of Mosul.
The Baiji refinery once produced some 300,000 barrels of refined petroleum products per day, meeting 50 percent of the country's needs.
