Authorities lowered the threat level but warned Britons to remain vigilant, saying they may still be the targets of terrorists after security forces foiled an alleged plot to bring down packed trans-Atlantic planes. The threat level was downgraded from critical to severe, reflecting an intelligence assessment that a terrorist attack remained highly likely but was no longer imminent. «I want to stress ... that the change in the threat level does not mean that the threat has gone away,» Home Secretary John Reid said at an early-morning news conference. «There is still a very serious threat of an attack. The threat level is at severe, indicating the high likelihood of an attempted terrorist attack at some stage, and I urge the public to remain vigilant,» he was quoted as saying by the Associated Press.
