A group of teenagers attacked another man as he walked home in Inwood on Saturday night, Nassau County police said.
Police said the victim, 36, was walking near Brunswick Avenue and Doughty Boulevard just before midnight when eight teenagers struck him from behind.
The teenagers continued hitting the victim in the head and back with what police called an "unknown object" until the victim fell to the ground, police said.
The teens them took his wallet and cellphone before running west on Brunswick Avenue, according to police.
The victim was taken to a hospital for treatment of head and ankle injuries.
Police said the group included four males and four females, all between 15 and 18 years old and all about 5-feet, 9-inches tall.
Police ask anyone with information about this case to contact Nassau County Crime Stoppers at 800-244-TIPS. All calls will be kept confidential.