Indian Point nuclear power plant tested its emergency siren system across the Hudson Valley this morning.

All 172 sirens sounded in Westchester, Rockland, Putnam and Orange counties for about four minutes between 10:30 a.m. and 11 a.m.

Plant officials stress that the sirens are not a signal to evacuate. In an actual emergency, the sirens would sound to alert the public to tune in to a local EAS radio or television station for important information and direction.

The plant is scheduled to be taken completely offline by 2021 after an agreement between Gov. Andrew Cuomo's office and Entergy, the company that owns Indian Point.