Investigators believe that the recent gas explosion that obliterated a nine-story section of an apartment building in Archangelsk, killing 58 people, may have targeted police officers living there, an official said Monday.

Russian investigators have discovered evidence that revealed "deliberate damage of the gas system including valves" in the building that exploded in the White Sea port on March 16, regional Deputy Prosecutor Yury Shperling said, Interfax reported. Shperling said investigators were looking into the possibility that the explosion could have been "a revenge attack" against police officers living in the building.

He said that authorities were also considering an earlier theory that the blast could have been triggered by vagrants who had stolen metal fittings from gas pipes to sell them for scrap.

Investigators are "looking for several people," but no arrests have been made, Shperling said.