TEHRAN, May 10 (Xinhua) -- A U.S. Air Force Lockheed Martin F-35 Lightning II fighter jet squawked 7700 emergency signal Sunday morning as it was flying over the Gulf of Oman, Iran's semi-official Tasnim news agency reported.

After sending the emergency code, the aircraft changed course toward the United Arab Emirates and began losing altitude, the report said.

In a separate incident on Tuesday, two U.S. Air Force aircraft, namely a KC-135R Stratotanker and a Boeing KC-46 Pegasus, carrying out operations over the Gulf, squawked 7700, according to Tasnim.

It cited flight-tracking data and regional reports showing that the KC-135 Stratotanker reportedly experienced an in-flight emergency over the Gulf and Strait of Hormuz and sent a distress code before vanishing from radar.

According to Tasnim, the Boeing KC-46 Pegasus sent the code while flying in Saudi Arabia's airspace on its way back to Israel's Tel Aviv. ■