An investigation is underway into an unsubstantiated bomb threat targeting a Senate office building in downtown Ottawa.

Ottawa Police received a call Thursday evening threatening to place a bomb in the Victoria Building on Wellington Street.

Ottawa Police, the RCMP and the Parliamentary Protective Service responded to the building, and a search concluded the building was secure.

The Parliamentary Protective Service continues to investigate.

The Victoria Building houses 40 offices for senators and has four committee rooms.