MOSCOW: Ten people died and scores were taken to hospital after a train derailed in Moscow's packed metro during rush hour on Tuesday, 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.
Georgy Golukhov, the head of Moscow's health department, had earlier said five people had perished and another 106 had been taken to hospital.
AFP correspondents saw several helicopters and dozens of ambulances at the scene outside Park Pobedy metro station in western Moscow.
"I thought it was the end," one passenger told state television channel Rossiya 24. "We were trapped and only got out through a miracle.
"There were lots of injured," he added. "Various injuries: heads, legs."
'Moaning with pain'
Alexei Naryshkin, a presenter on the popular Echo of Moscow radio station, posted a photograph on Twitter of rescue workers carrying a body in a black bag.
"They are laying out the injured. They constantly go down with stretchers. They carry them out. Some are unconscious. Some are moaning with pain," Naryshkin wrote.
Another witness, a young man in a polo shirt, told Life News television: "I got into the carriage and after about 20 seconds, the light went out and the train was just pulled apart. I was just thrown into the centre of the carriage."
"Panic started," he told Life News television.
"We climbed out of the carriages and we saw a blockage, men took hammers and pliers and broke it down and we walked on. The train was smashed, the chassis was just pulled apart."
Moscow mayor Sergei Sobyanin was at the scene and pledged to do everything possible to help the victims.
Golukhov said about 60 ambulances were stationed at the scene, while one seriously injured passenger was evacuated by helicopter.
Television footage showed rescue workers carrying the injured away on stretchers, while paramedics treated some on nearby grass verges.
A spokesman for the emergencies ministry said in televised remarks that the accident happened when a train braked suddenly after a false alarm.
"This is the most serious man-made disaster in the Moscow underground in its entire history," infrastructure analyst Alexei Khazbiyev told AFP.
"It is the most serious accident apart from terrorist attacks."
Opened under Stalin in 1935, Moscow's ornate metro is considered the world's busiest and carries some nine million people every day. (AFP)