BAGHDAD -- Backed by paramilitary forces and aerial support, Iraqi troops on Tuesday launched a new push to retake a key area north of the capital, Baghdad, and dislodge Islamic State militants from there, officials said.
The operation came as a group of suicide bombers targeted a military headquarters in western Iraq, killing eight officers on Tuesday. No one immediately claimed responsibility for that attack.
According to a statement by the Joint Operations Command, the "new offensive" began at dawn in a swath agricultural area northeast of the city of Samarra, 95 kilometers (60 miles) north of Baghdad, with the aim to cut IS supply lines and to tighten the grip around the IS-held northern city of Mosul.
The command says paramilitary forces, mostly Shiite militias, and the Iraqi air force were backing the push on the area, called Jazerat Samarra. The statement did not say if the U.S.-led international coalition was involved in the operation.
Controlling the Jazerat Samarra area will not only restrict the IS militants' movements between the three provinces in the region, but willalso be essential for future operations to retake parts of Anbar province and Mosul, said Sabah al-Numan, the spokesman of the counter-terrorism forces.
Al-Numan told The Associated Press that two vehicles loaded with militants were bombed on Tuesday, and that the security forces managed to hit a would-be suicide car bomber before he reached his target.
The offensive comes on the heels of two massive bombings in as many days by the Islamic State group in the area -- in the town of Muqdadiyah and in Baghdad -- that killed at least 110 people.
Shiite lawmaker and spokesman for the paramilitary forces, Ahmed al-Asadi, said the offensive "is in retaliation for the blood of our martyrs and to annihilate the terrorist gangs that have wreaked havoc."
Meanwhile, four suicide bombers disguised in army uniform struck at dawn at the military headquarters in the city of Haditha, 240 kilometers (150 miles) northwest of Baghdad, killing eight troops, including a local army commander, councilman Khalid Salman told the AP.
One of the bombers first attacked the gate of the building, then the others blew up themselves up when people gathered at the scene to help the victims. Salman said eight soldiers were also wounded in the attack.
IS still controls much of northern and western Iraq, but has been driven back in recent months in some areas, such as the cities of Ramadi and Tikrit. The government last month declared the western city of Ramadi, the Anbar provincial capital, "fully liberated" after it had been captured by IS last year.
Iraqi ground offensives -- despite heavy backing from U.S.-led coalition airstrikes -- have been slow in scoring key victories against the Islamic State. A campaign to retake Mosul, the main city held by Islamic State in Iraq, has long been believed to be imminent but has not taken off the ground yet.