An explosive was used in a blast that has killed at least four people during Bolivia’s Carnival celebrations, the second deadly explosion to hit the city of Oruro during the season, the country’s defence minister has said.

Javier Zabaleta told ATB television on Wednesday that the explosion caused a hole so large that officials do not believe it could have been caused by a gas leak, as was originally thought.

In his words: “It wasn’t a gas leak. We’re dealing with an explosive.”

Carnival dancers in Oruro, Bolivia (Juan Karita/AP)
Carnival dancers in Oruro, Bolivia (Juan Karita/AP)

He said officials were trying to determine if Tuesday night’s explosion is related to another, nearby blast that killed at least eight people on Saturday.

Mr Zabaleta did not speculate on a possible motive for an attack.

But Interior Minister Carlos Romero has said three people have been detained in the investigation.