Suicide attackers broke into a gas plant north of Baghdad on Sunday, killing at least seven people and setting fire to gas tanks, officials said.
The attack on the Taji plant, about 20 kilometres (12 miles) north of the capital, took place at around 6 am (0300 GMT).
Eight suicide bombers broke into the gas plant and blew up a car bomb at one of its entrances, interior ministry spokesman Saad Maan said in a statement.
Some of the attackers detonated suicide belts while others were killed by bullets, according to Maan, who said explosions set fire to three gas tanks.
Footage showed huge plumes of black smoke billowing into the sky but the Joint Operations Command said the fire had been brought under control.
The attack killed at least seven people and wounded at least 22, according to security and medical officials.
There was no immediate claim of responsibility for the attack but it bore the hallmarks of an operation by the Islamic State group.
The jihadist organisation has been steadily losing ground to the Iraqi security forces in recent months.
According to the government, IS controls only 14 percent of Iraqi territory, down from the 40 percent it held in 2014.
But the group has intensified its attacks behind the front lines, detonating car bombs in civilian areas and infiltrating sensitive sites with suicide commandos.
“Daesh (IS) is turning to targeting civilian facilities in cities after losing the battle on the front,” said Colonel Mohamed al-Bidhani, of the government’s “war media cell”.
On Saturday, a group of IS fighters snuck into Amriyat al-Fallujah, a government-held town west of Baghdad, in a similar suicide raid that killed five people.