LINO LAKES, Minn. (AP) — An Anoka County sheriff's official says "multiple fatalities" are likely following a helicopter crash in the Twin Cities suburb of Lino Lakes.

The aircraft crashed in a field near a residential area Thursday evening. Sheriff's Cmdr. Paul Sommer says it's too early to determine how many people were on the helicopter because "it's basically charred-up debris." Details about who was on board the helicopter remain unknown.

No one on the ground was hurt.

Sommer says witnesses reported seeing the helicopter's blade stop turning before it went down.

Federal Aviation Administration investigators will examine the wreckage. Authorities are asking nearby residents to contact Lino Lakes police if they find any objects that could be debris from the aircraft.

Lino Lakes is about 17 miles north of downtown St. Paul.