Chinese Foreign Ministry spokesman Lu Kang said Beijing had not received any information to indicate that there might be Chinese citizens on the plane.

Lu expressed deep condolences for those on board and sincere sympathy to their families. He said China would follow up with the search and rescue process.

Indonesian President Joko Widodo said he had ordered the National Commission for Transportation Safety to investigate the crash.

Speaking at a conference in Bali, he said rescuers were working to find victims, and urged Indonesians "to keep on praying".

He added that he felt the anxiety of the families of those on board the plane and hoped they could remain calm.

The plane's two black boxes, or flight recorders, had been located, a senior rescue official told Xinhua.

Soerjanto Tjahjono, an official with Indonesia's transport safety committee, said: "We will collect all data from the control tower. The plane is so modern, it transmits data ... and we will review that, too. But the most important (things) are the black boxes."

The agency received a report saying that air traffic control had lost contact with the flight.

The flight deck had been given permission to return to Jakarta before the crash. Yohanes Sirait, a spokesman for the Indonesian aviation authorities, said a request had been received from the cockpit for a return shortly after departure.

"The control tower allowed that, but then lost contact," he said. That was 13 minutes after takeoff.

Flightradar24, a Swedish internet service that displays real-time commercial aircraft flight information on a map, showed a rapid increase in speed and a loss of altitude in a final signal from the plane. This was indicated by a plummeting green line on a graph.

The plane only reached an altitude of 1,580 meters (5,184 feet) during the 13 minutes it was airborne.

Rescue agency spokesman Sutopo Purwo Nugroho posted photos on Twitter of debris that included a crushed smartphone, books, bags and parts of the aircraft's fuselage that had been collected by search and rescue vessels that converged on the area.

A telegram from the agency to the Indonesian Air Force requested assistance with the search in waters off West Java. Divers have been trying to locate the plane's wreckage.