Recovery efforts were underway after a plane crashed in Arizona’s Superstition Mountains Saturday morning, officials said.

The Pinal County Sheriff’s Office posted on Twitter that multiple people saw the plane go down, and that air support was able to confirm the crash site.

It was not immediately clear what type of plane was involved or how many people were on board the aircraft, which went down outside of the town of Apache Junction.

The Federal Aviation Administration has been alerted to the crash. No further information was immediately available.

The mountain range is about 40 miles east of Phoenix.