Woman plowed her car through a crowded street festival Saturday night, injuring about 35 people, including two police officers who drove their motor scooters into her path attempting to stop her, authorities said. Police said seven of the victims, including two children under age 3, suffered major injuries. Officers caught up with the driver, whom they identified as Tonya Bell, 30, of Oxon Hill, Md., near the site of the festival in the city’s Anacostia neighborhood. She was arrested and charged with aggravated assault while armed. The “armed” part of the charge refers to the car. District of Columbia Police Chief Cathy L. Lanier said additional charges are pending. Alan Etter, a spokesman for the District of Columbia fire department, said authorities believe Bell was going about 70 mph when she came through the festival. Witnesses described an extended period of mayhem in which the driver started off slowly through some closed streets and finally hit the accelerator on the avenue running through the heart of Unifest, an annual event sponsored by a church. The car hit a stage where people were dancing, witnesses said. Ryland Anderson, 19, and Philemon Walker, 24, told The Washington Post they were about to cross the street as the festival was winding down when the car sped past. They described strollers being flung into the air and said they saw the body of a man apparently lodged in the station wagon’s wheel well.