Washington: A classified US document obtained by the anti-secrecy group WikiLeaks shows three previously undisclosed participants in the Sept. 11, 2001 plot, The Washington Post reported on Tuesday.

The three Qatari men arrived in the United States on Aug. 15, 2001, conducted surveillance of targets and left the country on the eve of the Sept. 11 attacks, according to the leaked US diplomatic cable.

The three men "visited the World Trade Center, the Statue of Liberty, the White House, and various areas in Virginia" before flying on to Los Angeles, according to the leaked document.

A US official, speaking on the condition of anonymity, said the three Qataris were "looked at" within days of the attacks and that investigators concluded they could not be charged, The Washington Post reported.

"There is no manhunt," the official was quoted as saying. "There is no active case. They were looked at, but it washed out," he was quoted as saying, downplaying a report by Britain's The Daily Telegraph, which said the FBI has launched a manhunt for the previously unknown team of men suspected to be part of the attacks.

The CIA and the FBI declined to comment on the cable, the Post said.

The report said the three Qataris were part of a 2002 FBI list of people whom authorities wanted to interview about the Sept. 11 attacks.

After the men left the East Coast, they stayed at a hotel near the Los Angeles airport. Hotel staff later told investigators the men had "pilot-type" uniforms and computer printouts listing pilot names, airlines, flight numbers and flight times, the cable said.

The men were scheduled to fly to Washington on Sept. 10, 2001, on the plane that was hijacked the next day and flown into the Pentagon. Instead, they flew to London and then on to Qatar on Sept. 13, according to the report.

The three Qataris were part of a 2002 FBI list of people whom authorities wanted to interview about the Sept. 11 attacks, the Post said said.