Al-Qaeda hailed the suicide bombing at a CIA base in Afghanistan that killed seven agents as "revenge" for the deaths of top militants in US drone strikes, the monitoring group SITE said on Thursday.
A Jordanian doctor who was said to be a triple agent blew himself up at the base in Khost near the Pakistani border on December 30 in the deadliest attack against the CIA since 1983.
The head of Al-Qaeda in Afghanistan, Mustafa Abu al-Yazid, said the bomber wrote in his will that the attack was revenge for "our righteous martyrs" and named several top militants killed in drone attacks in Pakistan, SITE reported.
Yazid described the bomber Humam Khalil Abu-Mulal al-Balawi's mission as a "successful epic" to penetrate both American and
Jordanian intelligence, according to the statement published by the US-based SITE Intelligence Group.
He vowed that Qaeda would continue to fight the Americans "until they inflict upon them the greatest and most astonishing deaths and wounds."
The slain militant masterminds named by Al-Qaeda included Baitullah Mehsud, the leader of Pakistan's Taliban blamed for a wave of deadly attacks, notably the killing of former prime minister Benazir Bhutto in December 2007.
Mehsud was killed when a US missile slammed into his father-in-law's house on August 5 last year.
Abu Saleh al-Somali, described as part of Al-Qaeda's core leadership and responsible for plotting attacks in Europe and the United States, was killed in a drone strike in the North Waziristan area in December last year.
The Khost base has been described by US media as a key "anti-terror" facility that oversaw the drone strikes targeting Al-Qaeda and Taliban on the Pakistan border and a centre for recruiting and debriefing informants.
The Al-Qaeda statement surfaced after another round of attacks by the remote-controlled aircraft that left 11 militants dead in North Waziristan on the border with Afghanistan Wednesday, the first strikes since the CIA bombing.
The targeted area is a stronghold of Hafiz Gul Bahadur, who fought with the Taliban during the US-led invasion and is said to control up to 2,000 fighters whom he sends across the border but who do not attack in Pakistan.
Washington has put Pakistan at the heart of a new strategy for turning around the eight-year war against the Taliban in Afghanistan, hinging success on dismantling militant sanctuaries along the porous border.
Strikes by unmanned US spy planes have soared over the past year, with about 650 people killed since August 2008, and the extremists have vowed fierce retaliation.
But the attacks fuel anti-American sentiment in the nuclear-armed Muslim nation and the government publicly condemns the operations although analysts say they have Islamabad's tacit approval.
Balawi blew himself up at Forward Operating Base Chapman during a meeting with the CIA, killing seven agents and his Jordanian handler, who was a top intelligence officer and member of the royal family.
Jihadist websites have said that Balawi was a triple agent who duped Western intelligence services for months before turning on his handlers.
The Jordanian intelligence services, believing the bomber to be their double agent, had taken him to eastern Afghanistan with the mission of finding Al-Qaeda number two Ayman al-Zawahiri, the websites and Western intelligence agents cited by US media said.
Intelligence experts said it was possible the base let its guard down in searching the bomber because he was a coveted informant.
It was the deadliest single incident for the CIA since 1983, when eight agency employees were killed when Islamic militants bombed the US Marine barracks in Beirut, killing 241 Americans and 58 French.
The United States is increasingly reliant on the CIA and other covert forces to pursue its strategic goals. CIA and special forces were at the forefront of the US invasion of Afghanistan after the September 11, 2001 attacks, paving the way to overthrow the Taliban's extremist regime.