Authorities said Sunday that the bodies of seven people were discovered inside a twin home in a northwestern Minnesota city but did not say how they died. Police said the victims included four adults and three children. They were found just before 8 p.m. Saturday by family members conducting a welfare check at the home in Moorhead. Those family members called police. There were no signs of violence or forced entry into the residence, police said. Police are still investigating, but say "there is no known threat to the public," CBS Minnesota reported. "This is an absolute horrible tragedy, made even more poignant since it is close to the holidays," Moorhead Mayor Shelly Carlson wrote in a statement sent to the Star Tribune. "My heart aches for the family and friends who received this devastating news over the weekend. Our community mourns with them during this heartbreaking time." The bodies were taken to the Ramsey County Medical Examiner's Office in St. Paul, where autopsies will be conducted. Neighbors said the children were last seen Friday, KFGO radio reported. The children attended Moorhead High School and Reinertsen Elementary, CBS Minnesota reported. Grief counselors will be on hand Monday for students in the school district. Moorhead is on the Minnesota border next to Fargo, North Dakota, in a metropolitan area of about 230,000 people. Moorhead Police Capt. Deric Swanson said the investigation is still active and further information, including the cause of deaths and identification of the victims, will be released later.