Nine people have been killed and scores of others injured after two subway trains collided in Washington DC.
Rescue workers were continuing to search for survivors after one train crashed into the rear of another stationary train at about 5pm local time on Monday in the north of the US capital.
Fire department officials said 70 people had been treated for injuries, including at least two who were critically injured.
Rescue workers used cutting equipment to free people from the wreckage following the incident.
The collision on an above-ground stretch of track caused the front of one train to jackknife into the air and ride up on top of the other stationary train.
John Catoe, the subway system's general manager, said the first train was stopped on the tracks, waiting for another to clear the station ahead, when the trailing train, one of the oldest in the network's fleet, ploughed into it from behind.
Train rocked
The accident occurred on the Metro system's red line between Fort Totten and Takoma stations on the northeastern edge of the city near the border with Maryland.
Both trains were heading south into the city and so were less likely to have been packed with commuters.
PHOTO CAPTION
Fire and Emergency workers at the site of a rush-hour collision between two Metro transit trains in northeast Washington, D.C. Monday, June 22, 2009
Agencies