According to reports, the grenade was thrown at a group of people leaving a shop in the town of Piedecuesta.
One adolescent was killed at the scene and eight other people were seriously injured. The injured parties are receiving treatment in the town’s University Hospital.
Authorities suspect that the attack was the result of a fight that broke out in the area after a soccer match. The attacker is thought to have been inebriated.
Yesid Vasquez, of the metropolitan police, said that a person is suspected of the attack, and is being sought for questioning.