WASHINGTON, March 15: Senior Al Qaeda leader Khalid Sheikh Mohammed has apparently confessed to masterminding the 2001 terrorist attacks on the United States during a military hearing at the US base at Guantanamo Bay, Cuba, US officials said on Thursday.

The suspect, known by his acronym as KSM, is considered to have been the terrorist network’s third in command behind Osama bin Laden and Ayman al-Zawahiri.

KSM was captured in Pakistan in 2003 and handed over to American authorities who say that bin Laden and al-Zawahiri are still hiding in Pakistan’s tribal territory.

The Pentagon has released a transcript which quotes KSM as confessing: “I was responsible for the 9/11 operation from A to Z.”

The Pentagon identified KSM as a Pakistani national and said that during a military hearing, he confessed to planning a string of other attacks, including the 1993 attack on the World Trade Centre in New York, a nightclub bombing in Bali, Indonesia, and a failed attempt to bring down US airplanes using shoe bombs.

In all, KSM said he helped plan at least 28 separate terrorist attacks, which killed several thousand people.

In a section of the statement that was blacked out, KSM also confessed to the beheading of Wall Street Journal reporter Daniel Pearl in Pakistan.

The confession come in a statement he gave to a military hearing last Saturday at the US prison at Guantanamo Bay, Cuba.

The hearing was to determine whether KSM and 13 other prisoners meet US authorities’ definition of an enemy combatant, and can be kept in custody for another year.

The Pentagon also released transcripts from military hearings of two other suspected terrorists with ties to the region.

Yemen-born Ramzi Binalshibh allegedly helped KSM plot the September 11, 2001, attacks on the United States.

Faraj al-Libi, from Libya, allegedly masterminded two attempts to kill President Pervez Musharraf in 2003.

During the hearing, KSM reportedly began with pledging his allegiance to the jihad led by Osama bin Laden and finished with an admission to trying to destroy the American oil company in Indonesia owned by former Secretary of State Henry Kissinger.

He offered a chilling confession to “managing and following up on the Cell for the Production of Biological Weapons, such as anthrax and others, and following up on Dirty Bomb Operations on American soil,” the Pentagon said. He also named four other skyscrapers that were supposed to be destroyed in a “second wave” of attacks after 9/11.

They were the Library Tower in Los Angeles, the Sears Tower in Chicago, the Plaza Bank in Seattle and the Empire State Building in New York City.

“I shared responsibility for the assassination attempt against Pope John Paul II while he was visiting the Philippines,” the Pentagon quoted KSM as saying.

KSM’s lengthy closing oral statement began with a pledge to Allah in Arabic followed by a refusal to take an oath as part of the tribunal.