Terror Plot in London Foiled

(CBS/AP) Police in London say they have thwarted a major terrorist plot. According to the BBC, authorities say conspirators planned to blow up a number of planes flying to the U.S., using explosives hidden in carry-on luggage.

While few details have been made public, the BBC says the plot was uncovered and foiled by British police who have been conducting an undercover operation for a number of months.

An undisclosed number of individuals are reportedly under arrest.

Another report, on Sky News, says the plot may have involved blowing up 20 planes in mid-air over the Atlantic Ocean.

As a result of the plot, security precautions at British airports have been raised to the "critical" level, and long lines are the rule, with waiting time of 45 minutes just to check in, according to Sky News.

Extra measures in place including a ban on carry-on luggage, including purses too big to fit in a passenger's pocket. Passengers are allowed to take personal items - such as their passport, eyeglasses and cash - so long as they are in see-through plastic bags.

Eyeglass cases are not permitted. There are also rules on medicines: prescription medicines can be taken on board, in an amount necessary for the duration of the flight, unless they are in liquid form, in which case the authenticity of the medicine must be verified.

Contact lenses are allowed, but bottles of contact lens solution – which were eyed years ago as a potential terrorist tool – are not.

Keys are allowed as carry-ons. Electronic key chains are not, and all electric or battery-powered items, including laptops, cellphones, ipods, must be in checked, not carry-on, baggage.