(NBC) - The FBI has announced a $5,000 reward for information leading to the arrest of a ninja-like thief, who they say has carried out 11 armed robberies of stores in South Florida.

In each of the robberies, he enters the business, armed with a handgun and demands money from an employee, usually while wearing a unique face covering.

Authorities are searching for the man and ask anyone with information on his identity to call them at 305-944-9101.