ABC News reports the information about this plot comes from a suspected German terrorist who was caught on his way to Europe. The man is Ahmad S., who was captured in early July. Ahmad was linked to the Taiba mosque in Hamburg (The 9/11 mosque). German authorities closed down the mosque a month later.
In early September, Der Spiegel reported Ahmad S. had warned of possible terrorist attacks in Germany and Europe. Bernard Squarcini, head of France's counterterrorism and counterintelligence agency, said at that time that "All the lights are red. They are flashing from everywhere". Since then there have been four bomb alerts in Paris - two in the Eiffel Tower and two in metro stations - forcing police to clear out hundreds and thousands of people every time.
Via ABC News:
The captured German reportedly said several teams of attackers, all with European passports, had been trained and dispatched from training camps in Waziristan and Pakistan. Officials say the German claimed the attack plan had been approved by Osama Bin Laden.Via Sky News:
Travelers with German passports do not require a visa to enter the United States. Officials now believe at least one team of German jihadists was dispatched to Europe over the summer, travelling on German passports.
Sky's foreign affairs editor Tim Marshall said militants based in Pakistan were planning simultaneous strikes on London and major cities in France and Germany.
He said the plan was in the advanced but not imminent stage and the plotters had been tracked by spy agencies "for some time".
Intelligence sources told Sky the planned attacks would have been similar to the commando-style raids carried out in Mumbai.
Marshall said the European plot had been "severly disrupted" following intelligence sharing between Britain, France, Germany and the US.
It is not known whether the attackers are already in Europe.
The Wall Street Journal points to the Haqqani network as the possible planners. Ahmad S. is a member of the Islamist movement of Uzbekistan, as are many other German Jihadis. Meanwhile, there is at least one terrorist network which is still at large, linked to Ilyas Kashmiri and al-Qaeda.