Two pilots were reported missing after a Philippine Navy helicopter crashed Tuesday morning off Zamboanga City, a Navy spokesperson said. Its three passengers, however, have been rescued. The Navy Bolkov Helicopter PNH411 crashed into the sea between Great Sta. Cruz and Little Sta. Cruz Islands off Zamboanga City around 11:00 A.M., said Navy spokesperson Lt. Col. Edgard Arevalo. Arevalo said the ill-fated chopper, on a routine flight mission, was carrying two pilots, a crew member and two Navy passengers on board. The rescued were PO2 Rodolfo Pataueg, PO2 Noel Ridad, and PO2 Abdon Martinez, who have been taken to the Camp Navarro General Hospital. Navy men, including divers, are conducting an intensive search for the pilots. The identities of the pilots have not been revealed. According to a Navy report, the helicopter was on a routine flight mission to document Inshore Combat Tactics Training. All participating ships in the exercise immediately conducted search and rescue operations for the two pilots. — GMANews.TV Arevalo the Navy has yet to determine the cause of the crash.