Iraq says it has inspected three Iranian flights passing through that country en route to Damascus in the past week and found nothing suspicious.

Nasser Bandar, the head of the Iraq Aviation Organization, announced that no suspicious or prohibited materials or objects were found on the airplanes during searches carried out over the past three days.

Iraq has become strict in its inspection of Iranian flights to Syria since the U.S. called for the action on March 30.

Washington suspects Iran of delivering arms to the Syrian government and has insisted on tightening of flight checks for all Iranian airliners passing through Iraqi airspace.

Iraqi authorities have announced that in all their inspections they have only discovered first aid and medical supplies.