China tried to electronically jam U.S. drone flights over the South China Sea in a bid to thwart spying on disputed island military construction, U.S. officials said.

Global Hawk long-range surveillance drones were targeted by the jamming in at least one incident near the disputed Spratly Islands, where China is building military facilities on Fiery Cross Reef.

Disclosure of the jamming came as a U.S. Navy P-8 surveillance flight on Wednesday was challenged eight times by the Chinese military to leave the same area.

"This is the Chinese navy … This is the Chinese navy … Please go away … to avoid misunderstanding," a radio call in English from an installation on Firey Cross said. The warnings were reported by CNN, which had a reporter on the aircraft.

Later Thursday, the Navy released video revealing that the China's People's Liberation Army Navy sent several radio warning messages to the crew of the P-8 ordering the jet to leave the area, and to deviate from its flight path near Fiery Cross Reef.