Nassau police are looking for a man who held up two banks within 20 minutes, officials said.

Police said the man robbed the Citibank at 297 Merrick Rd. in Rockville Centre at 1:18 p.m. Tuesday and then robbed the Roslyn Savings bank at 3140 Long Beach Road in Oceanside at 1:40 p.m.

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Both times, the suspect entered the bank and handed a demand note to bank tellers. He was then given an undisclosed amount of cash from both banks, police said.

The robber was last seen in a blue Ford pickup truck, possibly a Ford Ranger, fleeing north on Long Beach Road after the second robbery.

He is described as being between 5 feet, 4 inches and 5 feet, 6 inches tall with a thin build and wearing a white T-shirt and jeans, and carrying a black drawstring bag, police said. A still shot of surveillance footage from one of the banks also shows the suspect wearing a black hat and dark glasses.

Anyone with information about the identity or whereabouts of this suspect is asked to call the toll-free Crime Stoppers hotline at 800-244-TIPS. All callers will remain anonymous.