WASHINGTON, Aug. 11 (Xinhua) -- The U.S. government knew "for days" about the terror plot targeting flights from Britain to the United States, CBS Television reported Friday.

    Hours after British police announced they had foiled a plot to simultaneously blow up planes over the Atlantic on their way from London to the United States, White House spokesman Tony Snow said Thursday that U.S. President George W. Bush had been briefed in advance and on Wednesday, at his ranch in Texas.

    Snow also revealed that Bush and British Prime Minister Tony Blair had held a lengthy teleconference on the matter on Sunday and had spoken again on Wednesday.

    Since the U.S. president was already aware of the situation, he was not awakened in the middle of night when British police decided to go public with their information and raise Britain's national threat level to "critical," the spokesman said.

    Senior U.S. lawmakers also received advance warning. Several of them said they had been briefed by the U.S. Homeland Security Department or CIA officials as early as Monday.

    Deputy Secretary for the Homeland Security Department, Michael Jackson said his agency had known for several days of the unfolding plot, but had waited for a signal from Britain to announce it.

    Some U.S. officials said anonymously that the suspects had planned to do a test run of the plot to see whether they could smuggle the equipment they needed aboard the targeted flights. The actual attack would have occurred within days.

    A congressman briefed by intelligence officials, who did not want to be identified because of the sensitivity of the investigation, said U.S. intelligence had intercepted terrorist chatter and British intelligence had helped thwart the plot through undercover work.

    Two other U.S. officials said British, U.S. and Pakistani investigators were trying to retrace the steps of the suspects in Pakistan and were seeking to determine whether a couple of the suspects had attended terrorist training camps there.

    The Bush administration on Thursday raised the threat level for flights from Britain to "red," designating a severe risk of terrorist attacks. It is the first time that the red alert level in the Homeland Security warning system has been invoked.

    All other flights, including all domestic flights in the United States, were put under an "orange" alert, one step below the highest level.

    The administration also banned all liquids and gels from flights, including toothpaste, makeup, and suntan lotion, but baby formula and medicines were exempted.

    It is unknown how long the new airline security rules will remain in effect. Enditem