MINOT (AP) - Police are investigating the death of an 18-year-old Minot State University student whose body was found in her off-campus apartment bedroom after her father came to the city to check on her.

Anita Knutson was found dead shortly after 5 p.m. Monday, in her northwest Minot apartment, Detective Bob Barnard said Tuesday.

Barnard said it appeared she was killed "by an unknown intruder who entered the home." No other details were immediately released.

"At this time, we are looking for the persons responsible," Barnard said. "We do not have a suspect at this time."

Knutson was originally from Butte, in north central North Dakota, and had just completed her first year at Minot State, Barnard said. She was a 2006 Velva High School graduate, he said.

Knutson's father had come to Minot on Monday to check on his daughter, Barnard said.

"He had not gotten any response at the door and he and the landlady entered the apartment and found the girl," Barnard said.

Knutson's body was sent to Bismarck for autopsy on Tuesday, Barnard said.

Police Lt. Dan Strandberg said authorities believe Knutson died sometime Sunday. He would not discuss a suspected cause of death or whether any weapon was found.