IRAN ( 2 Iranian Su-25 fighter Jets FIRE at U.S DRONE ) International airspace

DOD File

WASHINGTON (CNN) -

Two Iranian Su-25 fighter jets fired on an unarmed U.S. Air Force Predator drone in the Persian Gulf last week, CNN has learned.

The incident raises fresh concerns within the Obama administration about Iranian military aggression in crucial Gulf oil shipping lanes.

The drone was in international airspace east of Kuwait, U.S. officials said, adding it was engaged in routine maritime surveillance.