Police in Idaho announced Tuesday that the four University of Idaho who died Sunday were stabbed with a knife or blade.

Police responded to a call of an unconscious person in a private home near the campus and found four people dead. The deaths were all ruled as homicides.

"No weapons have been located...investigators believe that an edged weapon such as a knife was used," a police statement said.

The victims have been identified by officials as Ethan Chapin, 20; Madison Mogen, 21; Xana Kernodle, 20; and Kaylee Goncalves, 21.

"Investigators believe this was an isolated, targeted attack and there is no imminent threat to the community at large," the police statement added.

The University of Idaho is located in Moscow, Idaho. The city is located near the border of Washington and is about 300 miles north of Boise.

There are currently no suspects in custody.

A local official on Monday described the killings as a "crime of passion."

"Investigators are continuing to work diligently establishing a timeline of relevant events to re-create the victims' activities on the evening of Nov. 12 and early morning of Nov.13, following all leads and identifying persons of interest," police said.