Washington: Islamic radicals are being trained at "terrorist camps in West Pakistan and PoK (Pakistan-occupied Kashmir)" as part of a plan to send hundreds of operatives to "sleeper cells" in the US for carrying out terror attacks, media reports said.

According to intelligence and law enforcement officials, dozens of Islamic extremists have already been routed to Muslim communities in the US through Europe, the 'Washington Post' said quoting US and foreign officials.

Al-Qaeda sleeping cells, said the paper, are believed to be operating in 40 (out of 50) States, according to the Federal Bureau of Investigation (FBI) and other Federal authorities, awaiting orders and funding for new attacks in the US.

The information, the paper said, is based on secret intelligence data and information from terrorists and others detained by US authorities.

A high-ranking foreign intelligence chief is quoted by the 'Times' as saying in an interview last week that this clandestine but aggressive network of training camps "represents a serious threat to the United States, one that cannot be ignored".

"As many as 400 terrorists have been and are being trained at camps in Pakistan and Pakistan-occupied-Kashmir," the official said.

US intelligence officials said the camps, located in the remote regions of Western Pakistan and in Pakistan-controlled Kashmir, are financed in part by various terrorist networks, including al-Qaeda, and by sources in Saudi Arabia.