Al Qaeda is still planning Mumbai-style attacks in Europe, with the United States also possibly being targeted, CNN reported citing counter-terrorism officials in Europe and the United States.
The discovery of Al Qaeda's plans to launch coordinated attacks in several cities in Britain, Germany, and France led to the US issuing an unprecedented travel advisory in October for its citizens travelling in Europe.
European counter-terrorism officials cited by CNN say they believe the aim was to carry out the attacks before the end of this year. The expected timeframe of the plot had not previously been disclosed.
A former head of Germany's foreign intelligence service, Dr. August Hanning, told CNN intelligence indicated that Al Qaeda had already started planning to launch Mumbai-style attacks in the United States.
"We have got information that they have planned or are planning a plot like the Mumbai plot in Europe and the United States," said Hanning who retired late last year as State Secretary in Germany's Interior Ministry, one of the country's most senior counter-terrorism positions.
The revelation is the most concrete indication yet that Al Qaeda is planning mass casualty gun attacks on US soil, the news channel said in a report from Hamburg.
A senior US counter-terrorism official told CNN that US intelligence agencies have for some time been concerned that Al Qaeda would attempt to replicate on US soil aspects of the November 2008 Mumbai attack blamed on a Pakistani terrorrist group Lashkar-e-Taiba.
"The assumption has been that they would make plans to do this and the potential threat is being treated very seriously," the official told CNN.
The capture of Ahmed Sidiqi, a militant from the German port city of Hamburg, in Afghanistan in July, helped Western intelligence uncover the conspiracy, according to European and US counter-terrorism officials. Sidiqi is currently being held in American custody at Bagram air force base in Afghanistan.
Information came from "different sources ... and this is one of the sources," Hanning told CNN. His statement was echoed by a senior US counter-terrorism official.
Western intelligence agencies also learned that Ilyas Kashmiri, a senior Al Qaeda operative, had a planning role in the plot. According to US counter-terrorism officials cited by CNN, Osama bin Laden himself signed off on the plot.
Kashmiri, a veteran jihadist who made his name fighting Indian troops in Kashmir, has in the last year emerged as a key planner of Al Qaeda operations against the West, according to Western officials and court documents.
"[Kashmiri] knows our situation in Germany and therefore he is dangerous," Hanning told CNN.