The National Terrorism Alert website says there is concern worldwide about potential terrorism attacks utilizing new tactics.

Brian Ross of ABC NEWS reports there is now an "elevated" terrorism threat issued for  the United States and "all eyes are on Yemen."   Ross reports that Al Qaida may have trained "American-looking" women in Yemen for attacks in this country. The women may have U.S. passports. Adding to the anxiety, 6 people on the "no-fly" list reportedly tried to board flights to the United States last weekend.  

Two of the six were stopped at London's Heathrow Airport.  On Saturday, an Egyptian man on the no-fly list was stopped from flying on American Airlines flight 113 from London to Miami.  The next day, Sunday, a Saudi Arabian passenger was stopped from boarding United Airlines flight 929 to Chicago. Officials said the man was sent back to Saudi Arabia by the British. 

 In two other overseas cases involving people on the no-fly list, a man in Nairobi, Kenya was kept off a flight Sunday that would have connected in Amsterdam to Dallas, and a passenger attempting to fly on American Airlines to Los Angeles was stopped in Saint Maarten before he could board a connecting flight to San Juan, Puerto Rico, according to officials.

The upgrade from "substantial" means Brits must be "more aware," the Home Secretary said. "We still face a real and serious threat to the UK from international terrorism," said Alan Johnson, who declined to link the elevated scrutiny to the attempted downing of a Detroit-bound airliner on Christmas Day.

"We never say what the intelligence is and it would be pretty daft of us to do that," he explained. "It shouldn't be thought to be linked to Detroit or anywhere else for that matter." London will play host next week to two conferences on Afghanistan and Yemen-where Al-Qaeda in the Arabian Peninsula has been stepping up operations recently, the BBC notes. And direct flights from Yemen are no longer permitted to enter the UK because of security concerns.