Indonesian search teams in the Java Sea have detected pings believed to have come from the black box flight recorders of the missing AirAsia flight QZ8501, which disappeared from radars on 28 December.

The AirAsia flight ran into trouble on its way to Singapore from Surabaya, carrying 155 passengers and seven crew members on-board.

No survivors have been found and the cause of the crash is not yet known.

"Although the pings were detected at the place where the aircraft tail was found, the black box flight recorders could have separated from it."

So far, 46 bodies of passengers and crew have been recovered and those missing could be trapped inside the aircraft.

Although the pings were detected at the place where the aircraft tail was found, the black box flight recorders could have separated from it, Indonesian officials said.

Earlier this week, an unmanned underwater vehicle spotted the rear part of the aircraft at a depth of around 30m.

The search teams have loaded lifting balloons onto helicopters to recover the tail, reported Reuters.

Indonesia search-and-rescue agency head Fransiskus Bambang Soelistyo was quoted by the news agency as saying: "The divers are tying the tail with straps and then we will try (to lift it) two ways, floating balloons combined with cranes, so that the tail sector wouldn’t be damaged.

"Because we assume the black box is in the tail sector."

The black box is equipped with underwater locator beacons that emit pings for at least 30 days.