Two transit buses collided head-on near a Pentagon bus stop on Friday morning, injuring 23 people, including 10 defence department personnel, according to the Pentagon Force Protection Agency.The crash occurred shortly before 7.30am when an Omni Ride bus and a Fairfax Connector bus struck each other, prompting a major emergency response and disruption to mass transit services in the area.Emergency personnel transported 18 of the injured to local hospitals for further medical evaluation, while five individuals were treated at the scene. Authorities confirmed that among those injured were defence department personnel, accounting for nearly half of the total casualties.The Arlington fire department responded to the incident and confirmed the crash, but referred further inquiries to the Pentagon Force Protection Agency, the federal law enforcement agency responsible for security at the Pentagon.Following the collision, the Metro Access Road was closed as officials launched an investigation into the cause of the crash. The accident also led to significant disruptions in mass transit operations for several hours.Camera footage from the scene showed the two buses colliding. Officials said it remains unclear what caused the crash.(With inputs from agency)