If you see spoke and a lot of emergency vehicles around Newark Liberty Airport Saturday, don't freak out.

The Port Authority is warning aviation passengers and motorists that an emergency response exercise will be held from 10 a.m. to 1 p.m.

The exercise won't delay flight operations, but the public may notice simulated smoke and extra vehicles, it said. The exercise is meant to test the airport’s emergency plan for mutual aid response, the airport’s Aircraft Rescue and Firefighting unit and local emergency responders to train together.

The exercise will include members of the Port Authority Police Department, Newark, Elizabeth, Union County, Essex County police and fire departments, the American Red Cross and other emergency responders.