Four American university students have been found dead in suspected homicides.

The students, found dead in an off-campus home, were targeted and the killer or killers used a knife or other “edged weapon,” police disclosed on Tuesday.

Investigators were trying to establish a timeline to recreate the victims’ activities on Saturday night and early Sunday morning, “following all leads and identifying persons of interest,” the Moscow Police Department said in a news release.

The killings likely occurred in the early morning hours and the bodies were found around noon.

The students were killed in what is considered to be “an isolated, targeted attack and there is no imminent threat to the community at large,” according to police, who earlier said evidence from the scene led them to believe there was no broader risk. Police provided no information about that evidence or why they believe the victims were targeted.

Autopsies expected to be completed later this week could provide more information about how the victims were killed.

Police discovered the students’ bodies on Sunday as they responded to a report of an unconscious person at a home steps away from the campus. The victims were identified as Ethan Chapin, a 20-year-old from Conway, Washington; Madison Mogen, a 21-year-old from Coeur d’Alene, Idaho; Xana Kernodle, 20, from Avondale, Arizona; and Kaylee Goncalves, 21, from Rathdrum, Idaho.

The Idaho Statesman reported late on Monday night that investigators are seeking a suspect.

“All I can say is the deaths are ruled a homicide at this point, and homicide and murder are synonymous,” police Captain Anthony Dahlinger told the Statesman by phone. “We certainly have a crime here, so we are looking for a suspect.”

University of Idaho president Scott Green said the students were all “killed” under tragic circumstances, and Moscow Mayor Art Bettge said all four of the students were considered victims in the investigation. Dahlinger told the Idaho Statesman on Monday night that none of the deceased students are believed to be responsible for the deaths.

The four University of Idaho students were found dead in off-campus housing. Pictured: Kaylee Goncalves, left, and Madison Mogen. Photo / via Instagram

The students likely died between 3am and 4am, but they weren’t discovered for hours, Bettge said.

“The police got there at noon, nothing happened in the interim and nothing happened afterward, so it seemed to be a unique occurrence that was not apt to be repeated,” said Bettge. That timeline helped authorities determine that there was not an active risk, he said.

Dahlinger declined to confirm or deny Bettge’s description of the timeline.

The university cancelled classes on Monday, and said additional security staffers were available to walk students across campus if needed during the remainder of the week.

Still, the lack of information about the cause of deaths - and the fact that police have said there is no one in custody - had many parents worried about campus safety and some students leaving for Thanksgiving break early.

In a memo released on Monday afternoon, University of Idaho President Scott Green urged university employees to be empathetic and flexible and work with students who decided to leave classes to spend time with their families.

The four University of Idaho students who were found dead in off-campus housing were identified on Monday as Madison Mogen, 21, top left, Kaylee Goncalves, 21, bottom left, Ethan Chapin, 20, center, and Xana Kernodle, 20, right. They are pictured just hours before their untimely deaths. Photo / via Instagram

“Words cannot adequately describe the light these students brought to this world or ease the depth of suffering we feel at their passing under these tragic circumstances,” Green wrote of the slain students.

The police said anyone with information should contact the department and asked that people respect the privacy of the victims’ family and friends.

Brian Nickerson, the fire chief of the Moscow Volunteer Fire and EMS Department, said police were the first to arrive at the home. The first responders from the fire and EMS department didn’t go inside or transport anyone from the scene, Nickerson said.

The city of Moscow is a close-knit college town nestled in the rolling hills of north-central Idaho, about 130km southeast of Spokane, Washington.

Officers investigate a homicide at an apartment complex south of the University of Idaho campus. Photo / AP

The University said Chapin was a freshman and a member of the Sigma Chi fraternity, and Kernodle was a junior majoring in marketing and a member of the Pi Beta Phi sorority. Mogen was a senior also majoring in marketing and a member of Pi Beta Phi, and Goncalves was a senior majoring in general studies and a member of the Alpha Phi sorority, the university said. The university also had different home town listed for Chapin and Kernodle than the towns listed in the Moscow Police Department release: The school said Chapin was from Mount Vernon, Washington, and Kernodle was from Post Falls, Idaho.

A vigil for the slain students was set for 5pm on Wednesday on the University’s Administration lawn, University of Idaho spokesman Kyle Pfannenstiel said.

Shortly after Moscow police announced the homicide investigation, students at the University of Virginia were also told to shelter in place after police said a suspect gunned down fellow students on a bus as they returned from a school field trip. The shooting left three members of the school’s football team dead and two other students injured. The shooting touched off an intense manhunt Sunday, and authorities announced Monday that a suspect, Christopher Darnell Jones Jr, had been apprehended.