A chartered aircraft with 72 on board, including a Brazilian football team heading to Colombia for a regional tournament final, has crashed on its way to Medellin's international airport.
Medellin's mayor Federico Gutierrez said it was possible there were survivors from the flight which was said to be carrying players from first division Chapecoense.
"It's a tragedy of huge proportions," he told Blu Radio on his way to the site in a mountainous area outside the city, where the chartered aircraft is believed to have crashed shortly before midnight local time on Monday.
He said ambulances and rescuers were on their way.
It is not clear what caused the crash of the aircraft, a British Aerospace 146 short-haul plane, but Colombia had been hit by heavy rains and thunderstorms in recent hours.
Medellin's airport confirmed that the aircraft, which made a stop in Bolivia, was carrying the Chapecoense team from southern Brazil. The team was due to play on Wednesday in the first of a two-game Copa Sudamericana final against Atletico Nacional of Medellin.
A video published on the team's Facebook page showed players readying for the flight earlier on Monday in Sao Paulo's Guarulhos international airport.