WASHINGTON (FOX 5 DC) - Metro police are investigating an officer's use of force after he used a stun gun on an unarmed man Saturday at the U Street Metro station.

Cellphone footage shows the confrontation between the man and the officer. The officer deploys his taser and pins the man to the ground after a testy exchange of words.

Metro police did not identify the man, who they say provoked the officer by taking "an aggressive stance with a balled fist." They also did not identify the officer, who arrested the man for assault on a police officer and obstruction of justice.

Police say officers initially responded Saturday to a report of boys assaulting commuters with sticks on the station platform. They also heard the boys were threatening to shoot Metro passengers with fireworks. The complaining witness left the scene while officers detained two of the boys. Police found no fireworks, released the boys and pressed no charges.

The man who was tazed intervened after the officers handcuffed the boys. One witness told FOX 5 that the man was not related to the boys who police apprehended.

Metro police say one officer involved in the incident went to a DC hospital for a minor injury.


In the video player above, watch all the video currently available of the incident.