The number of deaths was released by acting police chief William Krampf at the end of a news conference. Several others were injured, including some who have been transported to hospital, Krampf said.
Officials said a single suspect had been taken into custody and was being questioned. The motive and whether the shooter had any connection to the newspaper was unknown.
Law enforcement authorities who briefed reporters stressed that the investigation was just getting under way, adding that further information would be forthcoming.
They said the building had been secured, meaning no other gunman had been found. But they said it was considered a crime scene and cordoned off as the investigation proceeded.
Officials said a single suspect had been taken into custody and was being questioned. The motive and whether the shooter had any connection to the newspaper was unknown.
Law enforcement authorities who briefed reporters stressed that the investigation was just getting under way, adding that further information would be forthcoming.
They said the building had been secured, meaning no other gunman had been found. But they said it was considered a crime scene and cordoned off as the investigation proceeded.