Police found several human remains in a river in Oklahoma as they continued to search for four missing friends who vanished while cycling.

The Okmulgee Police Department released a statement earlier this week announcing the disappearance of Mark Chastain, 32, Alex Stevens, 29, Mike Sparks, 32, and Billy Chastain, 30, who have been missing since Sunday, October 9.

Joe Prentice, the Okmulgee Police Chief, gave a press briefing on Friday saying that a passerby called the police to the Deep Fork River with reports of several objects floating in the river that resembled human remains.

When they arrived, authorities confirmed that the suspicious objects might be human bodies, and the Okmulgee Police Department and other local agencies were engaged in recovery.

According to Chief Prentice, the discovery brings more questions than answers. Police have informed the families; but no identification has been made yet.

In his press briefing, Chief Prentice said that if the remains in the river match the DNA of the missing men, then their investigations will switch from missing persons to finding out what happened to the men. They will conduct two separate investigations if the remains are not the missing men.

“We are still unsure how many people were dumped in the river. So far, we have recovered different human body parts and the search is still in progress.”

In an earlier statement, the Okmulgee Police Department said that all four men had left Billy Chastain’s home on Okmulgee’s west side at around 8 pm on Sunday, and all of them were riding bikes. They believe only two of the men carried their mobile phones with them but attempts to reach them were futile as the calls went to voicemail.

Mark’s wife reported three of the men, Mark and Billy Chastain, and Sparks missing. A few hours later, Steven’s mother also reported him as a missing person. 

When the reports were made, the police did not consider any foul play, and after conducting interviews with a few potential witnesses, there were reports of sightings of Stevens, Mark, and Billy. One person said they saw Stevens at a smoke shop in the city’s south side on Sunday afternoon, while another reported seeing the two brothers near a YMCA on Monday.

Chief Prentice said that the discovery of bodies in the river was enough evidence to consider foul play in the missing person case. There was no sign of the four men’s bicycles in the vicinity of the river.

The last of the four to have been heard from was Chastain, when he spoke to someone at his home at 5 pm on Sunday. Police traced his phone to an area on the South side of Okmulgee, but it was off.

The Okmulgee police chief said they would not give up the search until they found the four men. The latest update from the police says that they are yet to receive identifications from the medical examiner’s office.