An angry Attorney General, Ms Janet Reno, has ordered a new investigation into the FBI siege at Waco, Texas, six years ago following the agency's belated admission that it used potentially flammable CS gas canisters.
About 80 members of the Branch Davidian cult and their families, led by David Koresh, died when their compound burst into flames during the FBI assault on 19th April, 1993, following a 51-day siege.
The FBI and other police forces were widely criticised at the time for their handling of the final assault which resulted in the deaths of 25 children.
Over the past six years, the FBI has insisted during numerous investigations that it did not use "pyrotechnic" CS gas during the assault but only civilian gas. The agency has said that the fire was started on the orders of Koresh.
The FBI has now admitted that an agent fired two military-type gas canisters at the start of the assault but says that they were launched at a concrete bunker and bounced harmlessly into a field away from the wooden compound which went on fire two hours later.
Ms Reno, who had authorised the assault and later took "full responsibility" for it, was never told about the use of these incendiary devices. Yesterday she said at a press conference that she was "very, very frustrated" at the new information.
She said she was "very troubled" at the development. "I will continue to pursue this matter to get to the truth," she told reporters. "I intend the results of the review to be made public and I will not stop until I get to the bottom of this."
Ms Reno and the Director of the FBI, Mr Louis Freeh, who was not in charge during Waco, have ordered 40 agents to re-interview everyone who was at the Waco siege. The FBI spokesman, Mr John Collingwood, said that the agents are to report "within weeks" on all aspects of the use of military-type tear gas and why it took so long to be admitted publicly.
Republicans in Congress who were very critical of the FBI's handling of Waco at the time now say that they will hold new hearings. Mr Dan Burton, Chairman of the House Government Reform Committee said he was "deeply concerned by these inconsistencies" and intended that the committee will "get to the bottom of this".
It has also emerged that the Army's secret Delta Force antiterrorism squad may have been involved in the final assault at Waco although it is not supposed to be used in domestic police work. The Chairman of the Texas Department of Public Safety, Mr James Francis, has said that federal officials need to explain what the role of the Delta Force was on that day.
Some of the Branch Davidian survivors of the Waco siege have filed a wrongful death suit against the FBI and the new information has apparently emerged during the preliminary stages of the case.