WASHINGTON: The United States held hundreds of inmates who were either totally innocent or low risk for years and released dozens of high-risk Guantanamo inmates, according to leaked classified files. The new leaks reveal that inmates were held without trial on the basis of often seriously flawed information, such as from mentally ill or otherwise unreliable co-detainees or statements from suspects who had been abused or tortured, The New York Times reported Monday. In another revelation, a top detainee reportedly claimed that a nuclear bomb had been hidden somewhere in Europe to be detonated if Al-Qaeda chief Osama Bin Laden is ever caught or killed. The Times was among a group of US and European media outlets that also included The Daily Telegraph, NPR, El Pais, Le Monde, Der Spiegel and La Repubblica to receive 779 documents from the whistle-blowing website WikiLeaks. At least 150 Guantanamo detainees were innocent Afghans or Pakistanis, including drivers, farmers and chefs, according to the Telegraph. It said that overall, US military analysts considered only 220 of all the suspects in the George W. Bush-era “war on terror” ever detained at Guantanamo to be dangerous extremists. Another 380 were deemed to be low-ranking foot soldiers who traveled to Afghanistan or were part of the Taliban, the Telegraph reported. In dozens of cases, senior US commanders were said to have concluded that there was “no reason recorded for transfer” to Guantanamo Bay. Prison officials were aware in at least two cases that they were holding innocent men behind bars and even acknowledged that in writing in their prison files, and yet it took months for them to be returned to their home countries, according to the public radio station NPR. Meanwhile, about a third of the 600-some men who have been transferred to third countries were branded “high-risk” before being released or handed to other governments, The New York Times noted. According to the paper, the best-documented case of an abusive interrogation at Guantanamo was the questioning in 2002 and 2003 of Mohammed Qahtani, a Saudi believed to have taken part in plotting the Sept. 11 attacks. Qahtani was leashed like a dog, sexually humiliated and forced to urinate on himself, the paper said. Meanwhile, according to the Telegraph, senior Al-Qaeda commander Khalid Sheikh Mohammed claimed that the terrorist group had hidden a nuclear bomb in Europe and will unleash a “nuclear hellstorm” if Bin Laden was ever caught or killed. In their top-secret detainee assessments, analysts also provided fresh information about the self-proclaimed Sept. 11 mastermind. President Barack Obama's administration, which has struggled to shutter Guantanamo, denounced the “unfortunate” release of the classified documents, part of a massive cache of secret memos leaked to WikiLeaks last year. The US military classified Pakistan's top spy agency as a terrorist support entity in 2007 and used association with it as a justification to detain prisoners in Guantanamo Bay, according to leaked documents published on Sunday that are sure to further alienate Pakistan. One document given to The New York Times, says detainees who associated with Pakistan's Inter-Services Intelligence (ISI) “may have provided support to Al-Qaeda or the Taliban, or engaged in hostilities against US or coalition forces”. The ISI said it had no comment.