Authorities say an aircraft has crashed in the Superstition Mountains east of Phoenix but they don’t yet know what kind of plane it is.

A Pinal County spokeswoman says 911 calls began coming in around 6:30 p.m. Friday about an explosion near the Lost Dutchman Mine Park in the Apache Junction area.

Sheriff’s officials confirmed that some type of plane had crashed, and rescue crews were on their way to the crash site in rugged terrain near the peak of a mountain.

Video on Phoenix-area television stations shows several fires burning on the mountainside.

An FAA spokesman says there are no immediate reports of any missing commercial aircraft.

The size of the plane and number of people involved is unknown at this time.

The plane reportedly crashed near the top of the mountain at a height of approximately 4,500 feet.

Apache Junction Fire Department spokesman Dave Montgomery said crews are having difficulty accessing the site and it is possible the fire will burn itself out.

Crews from the Apache Junction Fire Department as well as the Pinal County Sheriff’s Office have responded to the mountain to assist in accessing any potential victims.

Details about the crash are developing.

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(Source: ABC 15)