Philippine investigators have retrieved the "black box" from the crashed military plane, the country's army chief has confirmed.
On Tuesday, Armed Forces of the Philippines chief of staff General Cirilito Sobejana said that another critically injured soldier died, which increased the death toll to 53, reports Xinhua news agency.
He said that seven of the 50 soldiers killed in the crash have been identified, while many of the victims were charred and "beyond recognition".
Aside from soldiers, Sobejana said three civilians were also killed and four others injured on the ground due to the impact of the crash.
The C-130 Hercules transport plane, carrying 96 soldiers and crew, crashed upon landing on Sunday on Jolo island in Sulu province.
The newly trained soldiers were being transported to Sulu to help fight terrorists.
The accident was the deadliest Philippine Air Force (PAF) plane crash in the past three decades.
Quoting one of the 46 soldiers who survived the crash, Sobejana said the military plane "bounced three times before it zigzagged and attempted to lift but failed to regain power".
One of the plane's wings slammed a tree, causing the aircraft to swerve to the right and crashed, he added.
Sobejana said that the flight data recorder could help determine the cause of the accident.
"We will hear from the black box what the last conversation of the pilots and crew members from the cockpit was," Sobejana said in a television interview.
Sobejana has instructed the investigators to complete the probe "as fast as they can", adding "they should be very deliberate".
President Rodrigo Duterte flew to Zamboanga City on Monday night to pay his respect to the victims and visit the survivors.