As many as 50 people were killed when an explosion, possibly caused by a human bomber, ripped through a train in the Russian capital on Friday. The explosion on the central Moscow metro railway occurred at 8.30 am (0530 GMT), the morning rush hour. A female bomber might have carried out the explosion, our correspondent reported, quoting Russian security sources. Human bomb attacks in Moscow and elsewhere in Russia have been the trademark of Chechen separatists fighting Russian forces. The blast occurred between the Paveletskaya and Avtozavodskaya metro stations. **Havoc*** Havoc reigned outside the Avtozavodskaya station, the closest to the train when the blast occurred, as distraught parents searched for their children outside. "My daughter is there!" a woman in her 50s, hair dishevelled, cheeks covered in tears, shouted over and over. "We saw them carrying bodies and injured covered in blood," said Lena, who works in a food shop 100 metres from the station. A short time after the blast "a man came into the shop, he was shaking uncontrollably and covered in blood. He said 'give me a vodka,'" she said. The man said that he was in another car of the train and walked out of the tunnel, past the affected carriage. "He told us that he saw arms, legs scattered around the carriage," Lena said. "He said it was bloody carnage." "It was an attack," said Kirill Mazulin, a spokesman for the Moscow city police, on the scene. "There is no doubt that it was a terrorist act," Mazulin said. **Survivors*** "The bomb was probably on a kamakaze terrorist" and had the power of one kilogram of TNT, Mazulin said. A fire raged as a result of the blast and smoke poured out of the station after the blast. More than a 100 ambulances and fire trucks rushed to site. More than 700 survivors of the blast, most of them Muscovites on their way to work, were evacuated from the metro nearly two hours after the blast. The incident took place just six weeks before a 14 March election for president in which the incumbent Vladimir Putin is widely expected to win a second Kremlin term easily. There was no immediate word from Putin who had been preparing to welcome visiting Azerbaijan President Ilham Aliyev. **PHOTO CAPTION*** Emergency Situations Ministry rescuers rush to the Paveletskaya metro station Friday, Feb. 6, 2004. (AP Photo/ Misha Japaridze)