Five people were killed and six wounded when gunmen attacked a bar in the Caribbean coastal community of San Antero, Colombian authorities said on Monday.
The slaughter took place on Sunday night, according to a statement issued by police in Monteria, capital of Cordoba province.
Four men armed with sub-machine guns arrived at the bar on motorcycles, walked inside and began shooting, police said.
The assailants "fired indiscriminately" at patrons, Cordoba Gov. Marta Saenz Correa said, citing witnesses accounts.
"This is harder every day," the governor said, adding that the bloodbath in San Antero brought to 409 the number of homicides committed in the province this year.
She attributed the attack to rivalries among what Colombian officials describe as "criminal bands": groups of former right-wing paramilitaries who are now engaged in drug smuggling, extortion and other rackets.
"Everything that is next to the sea remains a drug trafficking route," Saenz said.
Separately, police Sunday seized a cache of 115 grenades from a home near the southwestern town of Trujillo.
The ordnance belonged to one of the largest of the criminal bands, Los Rastrojos, according to police.
Some of the grenades were buried underground and the remainder were found on the roof of the house, the commander of the Valle del Cauca provincial police, Col. Julian Gonzalez, told reporters.