Two Metrobuses collided in southeast Washington, and several people are being evaluated for injuries.
One bus rear-ended the other at about 2:45 p.m. Monday near the intersection of Martin Luther King Avenue and W Street, D.C. fire department spokesman Pete Piringer said.
Initial reports listed nine riders with injuries. Because of the number of injuries, Piringer said the fire department declared it a mass-casualty incident and sent additional units to the scene. Piringer said there are more than six possible injuries, though they are likely not severe.
Traffic is expected to be affected in the area.
Metro said both bus operators have been taken out of service for routine drug and alcohol testing.