Another arrest in the British "airplanes" plot

CNN is reporting that another suspect has been arrested in connection the "airplanes" plot that was discovered last summer in Britain. Fourteen out of 24 persons that were originally arrested remain in custody and now, this fifteenth person, a 27-year-old man who was arrested in the Waltham Forest area of London, according to the London police.
No information was released regarding his specific role in the plot. As CNN reports:

Security sources said the alleged plotters intended to use an electrical charge to detonate liquid explosives in planes as they flew at maximum cruising altitude over the Atlantic Ocean, making it difficult for investigators to retrieve evidence.

These are some interesting details:

According to a British intelligence official, the planned near-simultaneous attacks -- which one top U.S. official said were intended to be "a second September 11" -- were foiled when a member of the country's Muslim community contacted authorities after noticing an acquaintance acting suspiciously.

An undercover British agent then infiltrated the group to gather information, U.S. government officials told CNN.