The White House says the terror plot to blow up six UK planes bound for the United States was a direct threat to the US.

August 12, 2006, 11:41 AM (GMT+02:00)

Five major American cities were targeted but not named. American officials reported the terrorists had planned to target flights to California, Washington and New York by United Airlines, American Airlines and Continental Airlines. The terror alert for incoming British flights was raised to red after the general level was put up to orange. The terror plot was suggestive of al Qaeda, according to US homeland security, which is sending federal air marshals to the UK.

New York Mayor Bloomberg announced extra security measures at international airports and baggage searches on the subways as a precaution.

All liquids have been banned on hand luggage in America. The suicide bombers were suspected of plotting to smuggle explosives aboard targeted flights in liquid form in hand luggage. Scotland Yard said 21 suspects, all British Muslims of Pakistani origin, had been arrested in the police operation and more were on the way. They said the terror plot was bigger than 9/11, would have involved deaths in “unimaginable” numbers and had “global dimensions.”

British national security alert has been raised for severe to critical.

The US alert was raised to one short of maximum after Prime Minister Tony Blair briefed President George Bush on the security threat to the planes.

UK police say this attack could have been bigger than 9/11. It was thwarted by a British covert anti-terror operation very close to its execution.

Britain’s airports were in a state of chaos and air ports across Europe were affected as security checks were stepped up and flight schedules thrown off. British Airways canceled more than 200 domestic and European flights. All flights in and out of London cancelled

Flights to the UK from Tel Aviv cancelled after Belgium, Lufthansa, Air France, Iberia and KLM canceled flights to UK.