An explosion at a nightclub in the northern Colombian city of Cucuta has killed one person and left at least 20 injured, police say.
It is not clear who is behind the incident, but police say they are investigating the involvement of drug gangs that operate in the area.
An unidentified man activated a grenade inside the packed disco, said police commander Carlos Rodriguez.
Seven such incidents have taken place in the city in recent years.
"A security committee will be called to discuss measures to address the problem," Colombian Government Secretary David Castillo told RCN radio.
Police say the explosion might have been an accident, with the man unwittingly activating the grenade he was holding.
But violent drug smuggling gangs have been involved in turf wars in the area, close to the Venezuelan border.