New scene of panic this morning in London: the police shot dead a man on the subway, at Stockwell station, in the south of the British capital. Pursued by plainclothes police officers, the man sought refuge in a metro train. He was caught by police, tackled to the ground and killed at point blank range, according to the account of a witness interviewed by the BBC. No information has yet been given on the identity of this man who is said to be of Asian origin.