OKMULGEE, Okla. (KFOR) – The Okmulgee Police said they have discovered human remains in their search for four missing men in the area.

The news comes as investigators have been canvassing the area all week looking for 32-year-old Mark Chastain, 30-year-old Billy Chastain, 32-year-old Mike Sparks, and 29-year-old Alex Stevens, who were reported missing on Monday by their families.

The Okmulgee Police Department previously confirmed the four were close friends and were believed to have left Billy Chastain’s house on the west side of Okmulgee on Sunday night, and all were reportedly on bicycles.

The discovery was made before 2p.m. Friday afternoon in a river that goes over Sharp Road, southwest of Okmulgee; a passerby told investigators they noticed something “suspicious” protruding out of the water and called the police.

“Officers responded and discovered what appears to be multiple human remains in the river [but] We don’t know that this is our missing men yet,” said Okmulgee Police Chief Joe Prentice, adding that multiple agencies, including the Oklahoma Highway Patrol Boat Team, were at the river to assist with the recovery process.

Phone data previously suggested that the men may have ridden out of town in the opposite direction of the river, and police said they hadn’t considered the area where the river is located.

“If it turns out that these four missing men are the remains in the river, then the focus of our investigation will shift from finding them to what happened to them [but] if it’s not them, then we’re back to square one,” Prentice continued.

While it is not yet known if the remains found were that of the missing men, Chief Prentice said the decision to inform the families of the men before the remains were positively identified was out of respect.

“We have more questions than answers,” added Prentice in a press conference Friday.

“At this time, we cannot make an identification, but out of respect, we let the families know before it was officially announced.”