An Iraqi army helicopter crashed late Saturday at a desert outside Abu Ghraib area, some 25 km west of Baghdad, killing all three crew members on board, a police source said on Sunday.

The helicopter suffered technical problems when it was above an area where the army was engaged in battles with anti-government tribal fighters and some militant groups in Iraq's western province of Anbar, the source told Xinhua on condition of anonymity.

The Iraqi government declared a 72-hour ceasefire in the nearby militant-held city of Fallujah late on Saturday to give a chance for the peaceful efforts to clear the city from al-Qaida fighters.