Jakarta. The National Search and Rescue Agency extended on Wednesday the search for victims of last week's Lion Air crash  and the aircraft's cockpit voice recorder.

The nearly new Boeing 737 MAX 8 passenger aircraft slammed into the sea north of Karawang district, West Java, on Oct 29, only 13 minutes after takeoff from Jakarta en route to Pangkal Pinang in Bangka Belitung. All 189 people on board flight JT-610 died in the crash.

"We have extended the operation for three more days," National Search and Rescue Agency (Basarnas) head Muhammad Syaugi told Reuters.

This was the second time the search had been extended.

But he said search teams from the military, police and others would stand down, leaving just his agency to press on.

"This operation has been running for 10 days and the results from combing the sea surface and the seabed are declining, therefore the resources of Basarnas should be sufficient," Syaugi told a news conference.

Basarnas had 220 personnel, including 60 divers, as well as four ships involved in the search and were focusing on an area with a radius of 250 meters, he said.

A police official said 186 body bags containing human remains had been retrieved and 44 victims have been identified after forensic examination.

The National Transportation Safety Committee (KNKT) has downloaded data from the flight data recorder last week, but search teams are still looking for the cockpit voice recorder.

A "ping" has been detected from the second black box but the signal was very weak, possibly because it was encased in mud," said Nurcahyo Utomo, an air accident official at the KNKT.

A vessel capable of sucking up mud was likely to be brought in to help, he told a news conference.

Boeing said on Wednesday that it had issued a safety bulletin reminding pilots how to handle erroneous data from a sensor in the wake of the Lion Air crash.

The United States-based aircraft manufacturer said investigators looking into the Lion Air crash had found that one of the "angle of attack" sensors on the plane had provided erroneous data.

Experts say the angle of attack is a crucial parameter that helps the aircraft's systems understand whether its nose is too high relative to the current of air – a phenomenon that can throw the plane into an aerodynamic stall and make it fall.

The KNKT said there was a problem with the sensor on the last flight taken by the doomed plane, from Denpasar, Bali, to Jakarta, even though one sensor had been replaced in Bali.

The KNKT has interviewed crew and technicians on duty for two previous flights, while also retrieving the faulty sensor from Bali for inspection.

It is planning to simulate a flight to assess the impact of sensor damage at Boeing's engineering simulator facility in Seattle, Washington.

Additional reporting by Tabita Diela in Jakarta, Tim Hepher in Zhuhai and David Shepardson in Washington

Reuters