GUATAPE (Colombia) • At least six people were reported dead and 31 are believed missing after a tourist boat sank in a reservoir in north- western Colombia.
The authorities have not said what caused the four-deck Almirante to go down in the El Penol reservoir in the tourist town of Guatape on Sunday.
The reservoir is 68km from the city of Medellin and is one of Antioquia department's main tourist draws, where Colombian and foreign tourists take leisure cruises.
An official said the victims were "all Colombians, and no minors".
The regional authorities said the boat was carrying 170 people, most of whom were rescued by other boats or escaped by themselves.
"It sank extremely quickly. It all happened in a few minutes," said fire service captain Luis Bernardo Morales.
One helicopter from the air force and two from the army were sent to help in rescue operations.
One survivor, Ms Laura Baquero, said on Colombian television that the two lower decks were "too crowded" and the passengers were not wearing life jackets.
"We started to feel like the boat was going to capsize," she said.
She also said there were "lots of children" on board.
But Colombian President Juan Manuel Santos said he had been told "the boat had a capacity greater than the number of people on board, so that it was not due to overloading" that it sank.
He said naval experts had come to investigate the cause of the sinking and divers would continue searching for people.
Videos circulating on social media show the ship going down and dozens of other vessels approaching it to try to rescue people.
"What we have seen in the videos is that the boat was very close to the port... and we do not know whether it was a mechanical failure, an overloading or something to do with the currents that caused it to sink," said Captain Morales.
He said rescuers were having difficulty reaching the reservoir by road due to heavy traffic on the major Medellin-Bogota highway. Guatape fills with tourists on long weekends, and yesterday was a holiday in Colombia.