Police in the US are investigating a detective who appears to draw his gun during a mass snowball fight on the streets of Washington DC.

Video taken at the scene shows people pelting a man with snowballs after his car, a Hummer, gets stuck in the snow.

The man - not in uniform at the time - then appears to pull out a gun while an angry crowd gathers and chants: "Don't bring a gun to a snowball fight."

DC police refused to comment, telling the BBC an investigation was under way.