Seven crew members killed in an Iraqi helicopter crash on Sunday in the easternprovince of Wasit. (Reuters Photo)

BAGHDAD, Nov. 12 (Xinhua) -- An Iraqi helicopter crashed on Sunday in Iraq's eastern province of Wasit, killing seven crew members, the Iraqi military said.

The Russian Mi-17 helicopter was on a training mission when it crashed in Wasit province, and "all of its seven crew members were killed," the media office of the Joint Operations Command said in a brief statement.

The statement did not give further details about the cause of the incident, but media reports quoted an army officer as saying that a technical malfunction caused the crash and the killing of the seven army personnel.

Iraq is gradually rebuilding its air force as it was one of the largest in the Middle East region after the former Iraqi President Saddam Hussein came to power in 1979 and during the eight years of the Iraqi-Iranian War which ended in 1988.

The air force downfall started during the Gulf War in 1991 after Saddam Hussein's regime invaded neighboring Kuwait, and continued during the 13 years of international sanctions. However, the remains of the Iraqi air forces were destroyed during the U.S.-led invasion of Iraq in 2003.

During past few years, the Iraqi army helicopter gunships have played an effective role in the fight against the Islamic State (IS) group, providing aerial support to the ground forces to drive out the extremist militants from their strongholds in northern and western Iraq.

Sunday's incident occurred as the Iraqi security forces are carrying out a major offensive to drive out IS militants from their last urban stronghold in Iraq's western province of Anbar.