Nassau police are investigating the robberies Wednesday night of a Williston Park Dunkin’ Donuts for the second time in five days and a Hewlett Carvel ice cream shop.

While police don’t believe the robberies are connected, they are the latest in a string of unsolved robberies involving masked, knife-wielding suspects.

In the Williston Park robbery, a male wearing a mask entered a Hillside Avenue Dunkin’ Donuts just after 8:30 p.m. Wednesday and ordered an employee at knife point to open the cash register before running west with an undisclosed amount of cash, police said.

StoryCops: Carvel latest in knife-point robberiesSee alsoRecent LI mug shotsDataLI crime stats

No injuries were reported, police said.

The suspect was heavy set, about 6 feet tall, and wore a white, hooded sweatshirt with dark block letters, jeans and boots, police said.

The same store was robbed at knife-point at about 10:30 p.m. Friday by a male in a white hooded sweatshirt, wearing what appeared to be a light-colored surgical mask and light-colored gloves, police said. Detectives are investigating whether the same suspect committed both robberies.

advertisement | advertise on newsday

About an hour after the Wednesday night Williston Park robbery, a male suspect who investigators suspect is responsible for at least nine armed robberies of mostly Dunkin’ Donut shops since March 1, held up a Carvel store at 1344 Peninsula Blvd. in Hewlett, police said.

The masked suspect went behind the counter and ordered an employee to open the cash register, police said. He took cash, then ran west toward Mill Road, police said.

No injuries were reported by the two employees there, police said.

The suspect was described as 6 feet tall and wearing a black, hooded sweatshirt, jeans, a ski mask, black gloves and dark, round sunglasses, police said.

Sunday night, police said, the suspect in the Carvel heist robbed a Massapequa Park Dunkin’ Donuts on Sunrise Highway.

Police ask anyone with information on any of the robberies to call Crime Stoppers at 800-244-8477.