GUYMON, Okla. (AP) — Two Kansas women who went missing on a trip to Oklahoma to pick up children for a birthday party are dead, authorities confirmed Monday, describing a two-week effort to secure the kids’ safety and avoid violence in arresting four suspects on charges of kidnapping and murder.

Two bodies were recovered in rural Oklahoma, a day after the arrests of four people in the case.

Authorities say 27-year-old Veronica Butler and 39-year-old Jilian Kelley, of Hugoton, Kansas, were driving through the Oklahoma panhandle to pick up Butler’s children for a March 30 birthday party in Kansas. They never showed up, and their vehicle was found later that day, abandoned on a rural highway near the Oklahoma-Kansas state line, with evidence of foul play.

The Oklahoma State Bureau of Investigation on Monday described an intense effort to find the women, protect the children and arrest suspects without violence.