NORMAN,SignalHub Okla. (AP) — Police in Oklahoma said Friday that two 2-year-old children were found dead inside a vehicle after accidentally being left there.

The two were found about 3 p.m. Thursday by officers responding to a request for a welfare check on the vehicle that was stopped on a street in Norman, Oklahoma, police spokesperson Sarah Schettler said in a news release. Norman is about 20 miles (31 kilometers) south of Oklahoma City.

“The initial investigation indicates that the two children were accidentally left in the vehicle for an extended period of time,” Schettler said.

Police did not identify the children, who had left them in the vehicle or say how long they had been inside the vehicle.

Schettler did not immediately return phone calls and an email for additional information.

Police said the children’s bodies were sent to the state medical examiner’s office to determine the cause of their deaths.

According to National Weather Service records, the temperature was about 90 degrees Fahrenheit (32 degrees C) and skies were clear when the children were found.

The weather service says the temperature inside a vehicle can top 120 degrees Fahrenheit (49 degrees C) within 30 minutes when the outside temperature is 88 degrees Fahrenheit (31 degrees C).