BROOKLYN - Police are investigating an armed robbery of a Kensington restaurant that was caught on a surveillance camera.Investigators say the video shows employees of Mister Tong's Restaurant on Fort Hamilton Parkway being held at gunpoint by two masked men Thursday.In the video, the suspects hold the workers down on the ground as they stuff a duffle bag with cash.So far, no arrests have been made. Anyone with information is asked to call Crime Stoppers at 1-800-577-TIPS.