I was stopped at a stop sign and when the light turn green I pressed the accelerator to move forward unfortunately, the vehicle hard braked for no reason. At first, I thought someone hit me from behind since there was no one in front of me but that was not the case. The braking was so violent that it caused my neck to snap back and forth, which caused the back of my head to hit the seat head support. I was going no faster then 10 mph but not slower then 5mph. In turn, the vehicle is available for inspection. My safety was at risk because I had no control or indicator that the braking was going to automatically brake on its own. The problem has not been reproduced or confirmed by the dealer or independent service center because the incident happened today (Sunday) therefore, I plan on making an appointment as soon as possible to see if they can identify any defects. The vehicle has not been inspected by the manufacturer, police, insurance representatives or others since I plan on taking it to the Mercedes dealer where I purchased the vehicle. There were NO warning lamps, messages or other symptoms of the problem prior to failure.