The Pentagon is investigating the source of a series of photographs released to the press of Al-Qa'eda and Taliban prisoners handcuffed, hooded and chained to the floor of a US military airplane, reports Anayat Durrani from Washington Four photographs of prisoners were featured on the Web site of American radio talk show host Art Bell. The station said the pictures were sent by an anonymous sender. The pictures also were e-mailed to several news organisations. The photographs give an inside look at the way prisoners were transported within Afghanistan and outside the country to places like the United States Navy base detention facility at Guantanamo Bay, Cuba. In the four photos prisoners are shown seated on the floor of the US military C-130 aircraft secured with white straps and guarded by US military personnel. In the photos, a large American flag can be seen hung from the ceiling of the aircraft above shackled prisoners wearing black hoods. US officials said the photos were not authorised and neither was its release to the public. Human rights organisations have sharply condemned the photos. US officials maintain that security measures taken in transporting detained terror suspects have not resulted in mistreatment of any prisoners. Commenting on the photos, Pentagon spokesman Lt Col Dave Lapan said, "There is no indication that the treatment of the prisoners is not in accord with official procedures." He added, "It is the taking and distributing of the pictures that is a concern." Pentagon spokeswoman Victoria Clarke said the Air Force and US Central Command were investigating the circumstances of the photos. "We have very, very tight restrictions on any images of the detainees for security purposes and because we have no interest in potentially holding detainees up for any kind of public ridicule," she said. "As people also know, we take great care to make sure the detainees have absolutely appropriate behaviour from when they are taken off the battlefield, in the course of transport, when they are kept at Guantanamo," Clarke said. "People also know but should be reminded we have the International Red Cross. Dozens of coalition representatives have been to Guantanamo to ensure that the treatment of detainees is absolutely appropriate." The legal status and conditions of the prisoners has long raised controversy worldwide. International human rights and civil liberties groups have demanded that the detainees be given prisoner-of-war status with rights under the Geneva Conventions. The US, however, does not recognise those detained as prisoners-of-war, but as illegal combatants. Concerns were heightened earlier this year after the release of photographs by the Defense Department that showed detainees in shackles and chains, blackened goggles, face masks and earmuffs. The Defense Department has been restrictive in the types of photographs it has allowed the news media to take of prisoners detained in the war on terror. The military takes photos for documentation purposes, but soldiers have been known to take their own memorable photos as well. Photos of American troops posing with American Taliban John Walker Lindh surfaced in the media. Soldiers were featured next to a handcuffed and blindfolded Lindh. One of the soldiers had apparently written an obscenity across the blindfold that covered Lindh's face. Meanwhile, US officials identified one of the five men killed in a CIA attack on suspected Al-Qa'eda in Yemen to be a US citizen named Ahmed Hijazi. Hijazi is believed to be linked to a suspected Al-Qa'eda cell in suburban Buffalo, New York. Among the others killed in the attack was Abu Ali, also known as Qaed Senyan Al-Harthi, believed by US officials to be Al-Qa'eda's chief operative in Yemen. The men were killed Tuesday after a CIA Predator drone aircraft fired a missile at their car. The attack marks a new phase in the war on terror. "The president has given broad authority to US officials in a variety of circumstances to do what they need to do to protect the country," said national security adviser, Condoleezza Rice on Fox News Sunday. "We're in a new kind of war, and we've made it very clear that it is important that this new kind of war be fought on different battlefields," she added. The attack was condemned by Amnesty International which sent a letter to President Bush and a letter of inquiry to Yemeni officials. In a statement the organisation called the targeted killings "extra-judicial executions in violation of international human rights law".