Colombian authorities are looking into reports that the plane carrying Brazilian footballers that crashed near Medellin may have run out of fuel.
There have been unconfirmed reports that the pilot had sent a radio message saying the plane was running out of fuel and needed to make an emergency landing – and that there were then electrical problems.
Investigators from Brazil have arrived in Colombia to join local counterparts following the crash that killed 71 people, wiping out the Chapecoense football team.
Experts from Britain, where the charter plane – a BAe 146 made by BAE Systems – was built, are also in the country to help the national authorities.
The two black boxes have been recovered but retrieving data may take a while.
The aircraft had flown from Santa Cruz in Bolivia, carrying the Chapecoense team and officials, as well as more than 20 journalists.
Colombian media, quoting investigators, have claimed that the plane was made to wait for another aircraft to land before its turn came.
A military source told AFP that the fact the plane had not exploded upon impact was suspicious, reinforcing the theory of a lack of fuel.
Brazil’s ambassador to Colombia spoke from the Rio Negro airport at Medellin where the flight was due to land.
“The families, as you can imagine, are in a very delicate situation. We tried to avoid them coming to Colombia so that they don’t have to through the additional stress,” Julio Glinternick Bitelli said.
An eyewitness filmed the scene at a local clinic as a survivor was brought in by ambulance.
All but six of those on board – three footballers, a journalist and two crew members – died in the crash.
The survivors’ injuries range from bruises to at least one amputated limb.
The Chapecoense team had risen through the divisions and were about to play the first leg of a Copa Sudamericana final, the biggest match of their history.
Investigators returned to the wreckage on Wednesday; soldiers had guarded the hillside crash site overnight.
Most of the bodies are said to have been recovered and many identified, with the help of medical experts from Brazil.
The bodies are to be repatriated to Brazil and Bolivia, the countries where the nine-person crew came from.