A hand grenade was set off late on Saturday evening in the Plaza del Chorro de Quevedo in La Candelaria, leaving three people injured.
The device exploded around 12.30am on August 16 and was soon followed by the sound of multiple emergency services sirens heading to the scene.
Nicky Gray, a freelance journalist at the scene of the incident, tweeted that he saw glass all over the street and that the explosion appeared to originate inside a local bar.
On Sunday, police confirmed that a hand grenade had been set off by three intoxicated people. All three were injured and taken to hospital. One was in a serious condition.
The police have ruled out terrorism in the incident.