Threat Level for UK to US Flights Raised to Severe

The U.S. Department of Homeland Security has raised the terrorist threat level to Red or Severe for commercial airline flights originating in the United Kingdom and bound for the United States. The threat level was raised in reaction to the arrest by British police of more than 20 persons suspected of plotting to blow up U.S.-bound jets.

Special Security Measures in Effect at US Airports
In addition, the Department of Homeland Security has raised the threat level to Orange, or High for all commercial flights commercial flights in the United States. The Transportation Security Administration (TSA) has implemented special security measures at all U.S. airports. Specifically, no liquids or gels including all beverages, shampoo, suntan lotion, creams, tooth paste, hair gel, and other items of similar consistency will be allowed in carry-on luggage. [Details from TSA]

"Currently, there is no indication, however, of plotting within the United States," stated Homeland Security Secretary Michael Chertoff in a press release. "We believe that these arrests have significantly disrupted the threat, but we cannot be sure that the threat has been entirely eliminated or the plot completely thwarted."

Also See:
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Chaos at Heathrow
So, You're Stuck in London