An explosion of a cistern not far from a gas station in Zagreb caused a moment of panic for the capital’s residents who thought it must have been an earthquake.

Both the gas station and the hotel located near the place where the explosion took place were evacuated.

Although the exact reason has not yet been determined, police suspect that human error could have caused the explosion as some workers were seen welding something on the cistern.

The explosion spread the fire to a driver cabin of another cistern and a tourist bus.

One of the workers at the gas station, Elvis Bokulic, witnessed the explosion.

"Everything shook. We first thought that it was an earthquake and we ran outside, to see everything in flames. They were 20 meters high," Bokulic said.

The quick intervention of firefighters contained further spreading of the flames, but the shaken residents remain gripped by fear, the daily Vecernji List writes.

A police investigation is underway