MINOT (AP) - Police are interviewing people about the killing of Minot State University student Anita Knutson but they have no suspects, an investigator said Thursday.

"We've done some interviews already. We're going to continue with some; we'll re-interview some," Lt. Dan Strandberg said.

He declined to say how many people had been interviewed, or discuss other details of the investigation.

"We don't have anybody specific that we can concentrate on at this point," Strandberg said.

Minot police said the body of Knutson, 18, of Butte, was found Monday by her father and a landlady in her apartment. They suspect she was killed by an intruder.

Knutson had just completed her first year at Minot State, after graduating from Velva High School.

Police are following up on other leads, including one from a woman who reported seeing a man running away from the area of Knutson's apartment building, Strandberg said.

Strandberg said the witness described the man she saw running as being about 6-feet-2-inches tall and 200 pounds with dark hair. She said he was wearing a white T-shirt and dark-colored shorts and was "like, running hard," Strandberg said.

Strandberg said he and five other officers canvassed the neighborhood on Wednesday night, going door to door and talking to dozens of residents, but "didn't turn up a whole lot of information."

He said the identity of the running man was still a mystery Thursday, but that he has little doubt about the credibility of the report. Officers had planned to complete the neighborhood canvas on Thursday.

Strandberg said police were still waiting Thursday for preliminary autopsy results.