At least six people died when a passenger boat sank on a reservoir in north-western Colombia.

Reports say 133 people were rescued, but 16 are still missing after the four-deck Almirante went down near the tourist town of Guatapé, 45 kilometres east of Medellín yesterday.

There were about 170 people aboard.

Eyewitness Juan Quiroz told the BBC that the boat sank in less than five minutes.

Leisure boats quickly came to the rescue, hauling victims from the water and the top deck of the vessel.

Army helicopters and divers have been sent to the scene.

A local government official told AFP news agency that “the situation looks serious”.

More than 20 people were taken to a hospital in Guatapé.

Colombian President Juan Manuel Santos, who travelled to the scene yesterday evening said six people had been killed, revising down an initial death toll of nine given by officials.

Luis Bernardo Morales, a fire service captain involved in the rescue operation, said the boat was very close to the port when it sank.

Guatapé is a popular Andean resort town, known for its water sports and recreational activities.