Two men have been arrested and charged with killing five people whose bodies were found at a St. Louis-area home over the weekend, authorities said.

Anthony Watkins and Terrance Wesley were charged with 20 counts each, including five counts of first-degree murder, five counts of attempted robbery, and 10 counts of armed criminal action, officials said at a news conference Tuesday.

"Any homicide takes a tremendous toll on the community. Any time we that have five homicides, it’s a horrific thing," St. Louis County Police Chief Jon Belmar said.

The five people found dead Saturday afternoon in an apartment in unincorporated St. Louis County have been identified as Derrick Penny, 54; James L. Penny, 54; Rodney E. Holt, 37; Rondall Mullin, 65; and Ronald Brewster Jr., 40.

Police said that all five died of gunshot wounds. A motive was not disclosed, and police said earlier Tuesday that the case remains an active investigation.

The St. Louis Post-Dispatch newspaper reported that court documents allege Watkins and Wesley tried to rob the victims at gunpoint and threatened to kill them, and that they later returned and fatally shot the five victims.

Belmar suggested that help from the community helped investigators.

"You've heard me speak before about the fact that we're looking constantly for assistance from our community," Belmar said. "This was the type of case, without getting into details, that the folks we were able to talk with were cooperative and we do appreciate that cooperation."

Police have said the victims were found dead after someone who had been at the residence Friday night returned and made the grim discovery Saturday afternoon.

Belmar said the two people charged have extensive criminal records, but did not elaborate. He said "there is an association with drug activity" but that "I don't think that it's appropriate necessarily to comment on a motive at this time."

Watkins and Wesley are being held without bond, NBC affiliate KSDK of St. Louis reported.

It was not immediately clear if either man had attorneys who could speak on their behalf. Phone numbers for anyone listed as possibly being related to either man could not immediately be found.