The FBI has warned President Barack Obama of the risks involved in transferring the Guantanamo Bay detainees to the US after the controversial prison camp is permanently closed, a media report said on Thursday.
Federal Bureau of Investigation (FBI) director Robert Mueller expressed concern about moving some 240 suspected terrorists into the US even if they are deemed to be no longer a risk, Geo TV said.
"The concerns we have about individuals who may support terrorism being in the US run from concerns about providing financing to terrorists, radicalising others, (and) the potential for individuals undertaking attacks in the United States," he said.
Although Mueller concedes that the detainees are unlikely to escape from the US jails.
"If you're talking about physical danger, in terms of being able to escape and undertake an attack - no," he said.
However, he said the Guantanamo detainees could still pose a threat.
"I will caveat by saying that in gang activity around the country, using it as an analogy, there are individuals that are in our prisons today, as I think you and others are familiar, who operate their gangs from inside the walls of prison," he said.
The Senate earlier voted overwhelmingly to block the transfer of detainees, and also turned down Obama's request for $80 million that he needed to close the prison.
The White House said Obama has not decided yet on the transfer of the detainees.
The prison camp at Guantanamo Bay in Cuba was established by the US military to try Al Qaeda suspects after the 9/11 terror attacks in US cities in 2001.