Three men have been arrested in London for possessing materials that could be used to carry out terrorist acts. The Sunday Times says the suspects were planning to release cyanide gas in the city's subway system, the Underground.Police wouldn't comment on the newspaper report but confirmed the arrests. A police source says they have not been charged with plotting a specific terrorist act. The men are being held in custody until their next court appearance on Monday. Last week, British Prime Minister Tony Blair advised his people to be vigilant against terrorism, but not allow fear to distort normal life. Copyright 2002 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.