Police north of St. Louis said Saturday that it appeared five people had been murdered overnight.

Their bodies were discovered Saturday afternoon in an apartment in unincorporated St. Louis County when someone who had been at the residence Friday night returned and found the adult acquaintances dead, St. Louis County police officials said at a news conference.

"One of the people who was here with them last night came back around noon-ish today, and that’s when the five people were discovered," Officer Tracy Panus said.

Authorities would not say how it appeared the five were killed, but Panus said, "We can tell that they are homicides. It is definitely a homicide at this point."

The complex where the bodies were found contains multiple boarded-up units, authorities said, but it was not immediately clear if the five were in such an apartment.

"Many of them are vacated but not all of them from what I understand," Chief Jon Belmar said.

The victims' identities have not been released yet.

"We have some information coming in," Belmar said, "but we need any help we can get from the public in this case."