Minister Pedro Sanchez said with "deep sorrow" that an Air Force Hercules had crashed on takeoff from Puerto Leguizamo, near the southern border with Ecuador.

State broadcaster RCN broadcast images of a badly damaged fuselage aflame in a forest clearing.

The aircraft can typically carry about 100 troops.

"Military units are already at the scene. However, the number of victims and the causes of the crash have not yet been confirmed," Sanchez posted on social media.

"It is a deeply painful event for the country. May our prayers bring some measure of comfort," said Sanchez.