'Foul play' suspected in case of missing moms in Oklahoma, police say

Two missing mothers in Oklahoma appear to be victims of "foul play," according to authorities, who are investigating why the women never appeared to pick up children as planned.

The Oklahoma State Bureau of Investigation said earlier in the week it is looking into the "suspicious disappearance" of Veronica Butler, 27, and Jilian Kelley, 39, after their vehicle was found abandoned over the weekend in a remote part of the state near the Kansas border.

"Based on the information obtained from the victim's vehicle, our investigators believe there was evidence to indicate foul play," the bureau said in an update on Wednesday.

There have still been no arrests and the women remain missing, police added.

The women were traveling together to pick up children when they went missing, the bureau said in a statement.

"They never made it to the pickup location," an earlier law enforcement advisory said. "Their car was located abandoned on the side of the road."

Their vehicle was found on Saturday in Texas County in Oklahoma -- south of Elkhart, Kansas, near Highway 95 and Road L -- the bureau's statement said. The local sheriff's office located the vehicle, OSBI spokesperson Hunter McKee told ABC News.

"There's every reason to believe that they could be in danger," McKee said. "It was a very rural area. They're nowhere to be found. ... The fact that we've had no contact with them for this long."

Both women are involved in church communities in Hugoton, Kansas, according to Butler's pastor, Tim Singer.

Kelley is the wife of a pastor at Hugoton First Christian Church, according to Singer.

Singer described the two mothers as "acquaintances" and said that they were picking up Butler's children to attend a birthday party when they went missing.

ABC News' Vanessa Navarrete contributed to this story.