ALLENTOWN, PA — A fiery car explosion in Allentown has left three men dead, officials announced late Sunday afternoon. The car exploded around 9:30 p.m. Saturday on Turner Street, near North Seventh Street.

Investigators suspect one of the victims was criminally involved in the blast, the Lehigh County District Attorney’s office said. The FBI said it will be involved in the investigation for as long as necessary.

People who were in the area during the blast took to social media to describe feeling fearful after the explosion. Graphic video showed a vehicle engulfed in flames with body parts — including a human hand — lying in the middle of the street. Fire engines blaring sirens can be heard as panicked bystanders stand cautiously back from the scene.

The area was eventually blocked off and residents were asked to shelter in place.

Police, the FBI and the ATF were investigating. The FBI tweeted that there is not believed to be any remaining threat to the public. Authorities are calling it an “isolated” incident, The Morning Call reported.

Those saw the blast or have information should call 215-418-4000.

Further details, including the names and identities of the victims and suspect, weren’t immediately released.

Photo credit: Harry Fisher/The Morning Call via AP