North Korea is using U.S.-made drones to reverse engineer its own fleet of unmanned Kamikaze aircraft, according to South Korean sources.

Citing an anonymous South Korean military official, Yonhap news agency said Pyongyang bought the American made MQM-107D Streaker targeting drone from a Middle Eastern country thought to be Syria.

The source added the North had mounted explosives and conducted tests, but had failed to build a functioning weapon.

The Steaker, which was built in the 1970s and used by the U.S. army for artillery and missile practice, flies at 40,000 feet and has a maximum speed of 575 miles per hour.

The source said: North Korea recently bought several U.S. MQM-107D Streakers from a Middle Eastern nation that appears to be Syria, and is developing unmanned attack aircraft based on them.

The source added the communist state would likely deploy the weapon near the maritime border with the South on the Yellow Sea.