One person was killed and two others injured in a shooting at a Long Island grocery store, Nassau County police said Tuesday.

The person killed was a 49-year-old employee at the West Hempstead Stop and Shop.

The shooting happened inside a manager's office, upstairs from the shopping floor.

At the time of the incident, there were "a couple hundred" people inside the store.

Nassau County Executive Laura Curran confirmed the incident, noting that "police are canvassing the area and schools nearby have been notified to lock down and secure their buildings."

She said the country's police department had asked all area residents to remain indoors since the suspect is not yet apprehended.

The Nassau County Police Department later named a person of interest in its investigations.

"The Person of Interest involved is Gabriel DeWitt Wilson, age 30. He is approx. 6'2" and wearing a black baseball hat and a black sweatshirt, and was last seen heading westbound on Hempstead Turnpike," the department said on Twitter.