British newspapers say Britain's terrorist attack threat level has been secretly lowered for the first time since the July 7 bombings in London.

The Sunday Telegraph and Sunday Times say the decision to lower the security threat level was made Thursday because intelligence agencies had no specific information on possible attacks.

Meanwhile, London police chief Ian Blair says he did not know his officers had killed an innocent Brazilian man at a subway station last month until a full day after the shooting incident.

British authorities have come under increasing criticism for the July 22 killing as conflicting reports emerge about circumstances leading up to the shooting of 27-year-old Jean-Charles de Menezes. Police wrongly suspected the man was a suicide bomber.

Britain's Home Secretary Charles Clarke has expressed confidence in the way police are handling the investigation.