Remains found over the weekend in Oklahoma have been identified as two Kansas women who went missing last month, authorities confirmed Tuesday. Their disappearance prompted a murder investigation that has led to four arrests.

The victims were identified by the state medical examiner as 27-year-old Veronica Butler and 39-year-old Jilian Kelley, the Oklahoma State Bureau of Investigation said Tuesday on social media. Official causes of death were not immediately given.

"Our thoughts and prayers are with their loved ones, along with everyone throughout their community," the agency said.

Butler and Kelley were reported missing March 30 under suspicious circumstances, OSBI said, when the vehicle they had been traveling in that day was found abandoned on a highway in Texas County, Oklahoma, just south of the Oklahoma-Kansas border.

At the time, a missing persons alert from Oklahoma Highway Patrol stated that Butler and Kelley had been "traveling to pick up children" before they vanished.

On Saturday, 43-year-old Tad Bert Cullum, 54-year-old Tifany Machel Adams, 50-year-old Cole Earl Twombly and 44-year-old Cora Twombly were all arrested on first-degree murder charges in the deaths of Butler and Kelley.

The bodies of Butler and Kelley were found a day later in rural Texas County, OSBI disclosed.

According to an unsealed affidavit, Adams is the paternal grandmother of Butler's children and the two were involved in a custody battle. Callum and Adams were in a relationship, the affidavit said. 

According to authorities, all four suspects belong to an anti-government group called "God's Misfits" that regularly met at the Twomblys' home and other locations, and they had allegedly tried to kill Butler before, according to a teenage witness who spoke to investigators.

Adams, who had allegedly searched the internet for gun stores and "taser pain level," purchased five stun guns at a local gun shop a week before the two women disappeared, the affidavit said. Investigators also found that Adams had bought several "burner" phones and "all three phones were at the area where Butler's car was located and the last known location of Butler and Kelley," the affidavit read.

Blood and a broken hammer were found near the abandoned vehicle, the affidavit stated.

In:
• Oklahoma
• Murder

Jordan Freiman

Jordan Freiman is an editor and writer for CBSNews.com. He covers breaking news, trending stories, sports and crime. Jordan has previously worked at Spin and Death and Taxes.