LONDON (AP) - London police say a second man has been arrested in connection with the London subway attack. Police said Sunday that a 21-year-old man was arrested late Saturday night in Hounslow in west London and is being held under the Terrorism Act. He is being questioned at a south London police station but has not been charged or identified. Two men are now in custody for possible roles in the bombing attack on a rush-hour subway train Friday morning that injured 29 people in London. An 18-year-old man was arrested Saturday in the departure area of the port of Dover, where ferries leave for France.