Moscow: Nineteen people have died and over 100 taken to the hospital after a train derailed in Moscow's packed metro during rush hour today, city authorities said.

The accident is believed to be the most serious in the eight-decade history of the city's metro system, the world's busiest. Russian national television described scenes of chaos on the packed underground system, saying passengers fell like dominoes when the train braked abruptly. "Right now 10 people (are dead)," the city's deputy mayor Pyotr Biryukov told journalists at the scene as the rescue operation continued, with about five people still believed to be trapped underground.