A tour boat with some 150 passengers on board capsized Sunday afternoon in the Penol-Guatape Reservoir, in Colombia's northwest department of Antioquia, said local authorities.
Rescue workers and officials were on the scene to help survivors and investigate the cause. It was not known how many died of drowning yet.
"We have a full operation underway," Victoria Eugenia Ramirez, secretary of the government of Antioquia, told reporters.
"According to the company, 150 people were on board. The rescue operation includes the Interior Ministry, air force, army and police. The boat 'El Almirante' (The Admiral) did not crash into another, it just sank," Ramirez added.
"The Admiral" is a four-level tour vessel, according to Colombian news network Caracol.
