According to the Nassau County Police Department, just before 6:30 p.m. Monday on Post Avenue in downtown Westbury, the suspects threatened to stab a 19-year-old girl.
They demanded everything she had with her, police said, and took off with two iPhones and a wallet.
No injuries were reported.
The subjects are described as Hispanic men, and 15-19 years old
Police are asking anyone with information on the case to call 1-800-244-TIPS.