A "vicious dog" evaded police officers near the Boston Marathon​ finish line on Thursday, prompting an officer to fire their gun.

The dog was alive when police got it under control and placed it in the rear of a cruiser until city animal control personnel could take custody, according to police transmissions.

The decal installation at the finish line of the Boston Marathon was interrupted by a flurry of police activity this morning that turned out to be a response to a “vicious dog” in the area.