Police are searching for two men they said robbed a Capital One Bank branch on Merrick Avenue in Merrick at gunpoint at about 5:45 p.m. on Monday.
Nassau County police said four employees were in the bank at the time, but said no one was injured.
It was not clear how much money was taken.
Police said one suspect is between 5-foot-4 and 5-foot-6 and was wearing a baseball cap and a long-sleeved red shirt.
The second suspect is believed to be about 5-foot-8 or 5-foot-9 and was wearing a gray shirt and a blue bucket-style hat, police said.
Both suspects are believed to be in their 20s -- and police said both were armed with handguns that were displayed during the robbery.
Police ask anyone with information to call Crime Stoppers at 800-244-TIPS. All calls will remain confidential.