Washington ? As many as three U.S. missiles aimed at targets in Iraq may have landed in Iran, two officials at the Pentagon said Saturday.

The State Department assured Iran, in a message sent through Swiss intermediaries, that the United States was investigating. Spokesman Philip Reeker offered public assurances that the United States respects Iran’s sovereignty and territorial integrity.

The official Iranian news agency reported that four rockets have landed in Iran during the past two days.

U.S. and Iranian officials are discussing the matter and Iran realizes that any strike was unintentional, said the officials, speaking on condition of anonymity.