UK Terrorist Group Was Infiltrated By British Agent

Fox News has the number of suspects arrested in the UK terror plot now at 24, rather than the 21 previously reported. They also report that:

The plot was foiled when an undercover British agent infiltrated the UK-based group, and passed information to authorities, FOX News has learned...

Meanwhile, the DHS raised the terror alert level for commercial flights from Britain to the U.S. to code-red. It's the first time the U.S. has raised the alert level to its maximum since the system was instituted in March 2002. Chertoff said the decision to raise the alert level was made after British officials bumped their terror alert level to their highest.