Sarajevo - An apartment building in the downtown Sarajevo, in which one person was killed and three injured in a gas explosion three days ago, was evacuated Wednesday after its residents complained they could smell gas.

Experts of Sarajevo Gas Company immediately deployed to investigate.

On Monday Bosnian police detained four people on suspicion of unintentionally causing a gas explosion at the building in the very centre of Sarajevo.

Those detained included the director, technical expert and workers of Viner Projekt, a company that had been testing terrain in front of the building where the explosion occurred.

They had reportedly punctured a gas line in front of the building.

The explosion caused a fire on the top floor of the four-storey building, completely destroying three apartments and shattering windows in surrounding buildings and nearby cars.

According to Sarajevo hospital's official, three injured people remain in critical condition. (dpa)