JAKARTA, Indonesia – Investigators have been able to recover hours of data from a flight recorder on a crashed Lion Air aircraft, as Indonesian authorities extended Sunday searches for casualties and debris at sea.

Vice President of the National Committee for Transportation Safety, Haryo Satmiko, said at a press conference that 69 hours of flight data had been downloaded from the recorder, including his flight fatal.

The Boeing 737 MAX 8 crashed a few minutes after taking off from Jakarta on 29 October, killing 189 people on board during the worst air disaster in the country since 1997.

The flight data recorder was found Thursday by divers in a damaged state and investigators said that he needed special treatment to retrieve his information. The cockpit voice recorder has not been found, but researchers are focusing on a particular area based on a weak locator signal.

The head of the National Agency for Search and Rescue, Muhammad Syaugi, said Sunday that the search operation, which was in its seventh day and involved hundreds of staff and dozens of vessels , would continue for another three days.

Syaugi paid tribute to a volunteer diver, Syahrul Anto, who died during the search on Friday. The 48-year-old family refused autopsy and he was buried Saturday in Surabaya.

More than 100 body bags of human remains have been found. Syaugi said that the number would continue to increase and that the remains were also washing on the ground.

He added that weak signals, possibly from the cockpit voice recorder, had been located but that no object had yet been found because of the seabed mud.

The flight tracking websites show that the aircraft had an erratic speed and altitude during its 13-minute flight and a previous flight the day before between Bali and Jakarta. Passengers on the Bali flight reported terrifying descents, and in both cases the various cockpit crews requested to return to the departure airport shortly after take-off. Lion said that a technical problem had been solved after the Bali fight.

Mr. Syaugi stated that a considerable amount of "skin" of the aircraft had been found on the bottom of the sea, but not a large part of his fuselage, as he had indicated, was possible Saturday.

He and other senior officials, including the army chief, plan to meet families Monday to explain the search operation.

The Lion Air crash is the biggest air disaster in Indonesia since 1997, when 234 people died in a Garuda flight near Medan. In December 2014, an AirAsia flight from Surabaya to Singapore sank into the sea, leaving 162 people dead.

In 2007, Indonesian airlines were banned from traveling to Europe for security reasons, but several were allowed to return to service in the next decade. The ban was completely lifted in June. The United States lifted the decadelong ban in 2016.

Lion Air is one of the youngest airlines in Indonesia, but has grown rapidly, serving dozens of domestic and international destinations. It has developed aggressively in Southeast Asia, a rapidly growing region of more than 600 million inhabitants.