JAKARTA, Indonesia (AP) — An aerial search for victims and wreckage from a crashed Indonesian plane expanded Thursday as divers continued combing the debris-littered seabed looking for the cockpit voice recorder from the lost Sriwijaya Air jet.

The Boeing 737-500 disappeared Saturday minutes after taking off from Jakarta with 62 people aboard. The other black box containing flight data was recovered Tuesday, and search personnel have also recovered plane parts and human remains from the Java Sea.

The aerial search is being expanded to coastal areas of the Thousand Island chain “because plane debris and victims may be carried away by sea currents,” said Rasman, search and rescue mission coordinator for the National Search and Rescue Agency, who uses one name.

Navy officials have said the two black boxes were buried in seabed mud under tons of wreckage between Lancang and Laki islands in the Thousand Island chain north of Jakarta. At least 268 divers were deployed on Thursday, almost double the previous figure.

The head of the navy’s underwater rescue unit, Col. Wahyudin Arif, said the plane apparently hit the water nose first, causing its wreckage to pile up in one area at a depth of 25 meters (80 feet). Divers were having difficulty removing broken pieces of the plane to retrieve the voice recorder.

“We have to be careful in removing the wreckage’s sharp objects, which could hurt the divers,” he said, “This is slowing our search effort.”

Rescuers increased to 4,100 personnel, supported by 13 helicopters, 55 ships and 18 raft boats.

So far, searchers have sent 180 body bags containing human remains to police identification experts. Families have been providing DNA samples to the disaster victim identification unit, which on Wednesday said it had identified six victims, including a flight attendant and an off-duty pilot.

The 29-year-old flight attendant, Okky Bisma, was buried on Thursday.

Relatives and friends carried his coffin to the cemetery in eastern Jakarta, followed by dozens of people, most wearing masks and maintaining social distancing because of the pandemic.

The airline said both pilots flying the plane were experienced and had good safety records.

Capt. Afwan, who uses one name, began his career as an air force Hercules pilot and had several decades of flying experience. He was known as a devout Muslim and preacher. The co-pilot, Diego Mamahit, was equally qualified.

Nurcahyo Utomo, an investigator with Indonesia’s National Transportation Safety Committee, said the crew did not declare an emergency or report any technical problems before the plane plunged into the sea.

He said investigators are working to read the data from the flight data recorder that was salvaged earlier and tracks information such as airspeed, altitude and vertical acceleration in an attempt to determine the cause of the crash.

The 26-year-old plane had resumed commercial flights last month after almost nine months out of service because of flight cutbacks caused by the coronavirus pandemic.

Investigators and experts from the U.S. National Transportation Safety Board, engine maker General Electric and Boeing are to join the investigation in the next few days.

Indonesia’s aviation industry grew quickly after the nation’s economy was opened following the fall of dictator Suharto in the late 1990s. Safety concerns led the United States and the European Union to ban Indonesian carriers for years, but the bans have since been lifted due to better compliance with international aviation standards.