Some 31 people were injured in the blast with 11 sustaining serious wounds, local media reported. As several people were wounded as a result of the explosion, others were hurt in a stampede.
The incident took place at midnight local time in the Bora Bora nightclub.
Óscar Aníbal Suárez, the mayor of the Caucasia municipality has revealed that a man and a woman were behind the attack. The alleged perpetrators have been detained, according to reports.
The video from the scene shows medical personnel boarding people from the nightclub to ambulance vehicles.
Another video allegedly shows the chaos inside the club following the blast.
TWEET: Two men reportedly captured in a grenade attack that left 40 wounded in Caucasia