Colombian police raided a bar in Bogotá early Sunday, triggering a stampede that left six people dead and five injured.
According to local media reports, more than 180 people were crammed into the small bar, called Night Club, when police were called in to break up a brawl.
Patrons started stampeding to get out when some type of gas was released inside the bar.
Victims were reportedly either smothered or crushed to death.
Witnesses have accused police of causing the deaths by using excessive force and throwing tear gas.
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"There must be an investigation as to how this gas came to be inside this place and that's why the attorney general's office is involved," Bogota Police Chief Luis Eduardo Martinez said.
The owner of Night Club, Luz Marina Pena, said police threw the gas when they were unable to enter the bar because the doors were locked.
"They began pounding down on the door and throwing tear gas below," she told reporters.
"They came in like animals, hitting people, clashing with the doorman. People began to choke. I opened the door for people to leave and police would not let them."
A federal probe has now been launched to investigate the incident and two of the officers involved have been suspended.
Bogotá police said the bar, located in the southern Restrepo neighborhood, has previously been closed four times for bad behavior.