Cuban officials say they have found one of the two black boxes from a plane that crashed near Havana airport, killing more than 100 people, in “good condition”.
Transport Minister Adel Yzquierdo says he hopes the second device will be recovered soon.
He revised the official death toll up to 110 people, including 11 foreigners.
Three women survived the crash, but are said to be in a critical condition with serious burns.
The incident is Cuba’s worst air disaster in decades, and two days of national mourning began on Saturday.
Officials said investigators are combing through the wreckage of the plane, a Boeing 737 which was nearly 40 years old, at the field where it crashed some 20km (12 miles) south of the Cuban capital.
The black box which has already been recovered will hold key flight data and information about what happened to the plane.
What do we know about the dead
Mr Yzquierdo told journalists that the 110 dead included 99 Cubans, six Mexican crew members, two tourists from Argentina, one from Mexico, and two passengers from Western Sahara.
“We heard an explosion and then saw a big cloud of smoke go up,” Gilberto Menendez, who runs a restaurant near the crash site, told Reuters.
Mexico’s transport department said on its website that “during take-off (the plane) apparently suffered a problem and dived to the ground”.
What about the survivors?
Four people initially survived the crash but one died after being taken to hospital, the director of Havana’s Calixto Garcia hospital, Carlos Alberto Martinez, told Reuters.
The three survivors are all women, according to Cuban Communist Party newspaper Granma: one aged between 18 and 25, one in her thirties and the third aged 39.
What do we know about the plane?
The plane had been leased to state airline Cubana de Aviación by the Mexican company Aerolineas Damojh.
The Mexican authorities said the plane was built in 1979 and had been successfully inspected last November. Mexico earlier said it was sending two civil aviation specialists to join the investigation.
How does this compare to recent plane crashes?
According to industry research, last year was the safest in history for commercial airline travel with no passenger jet crashes. But there have been several serious air disasters this year.
Cuba’s deadliest air crash was in 1989, when a Soviet-made Ilyushin-62M passenger plane crashed near Havana, killing 126 people on board and another 24 people on the ground.