The suicide bombing at a CIA base in Afghanistan was in revenge for the deaths of al-Qaeda militants killed in US drone attacks, the terror organisation claims.

The Jordanian triple agent Humam Khalil Abu-Mulal al-Balawi blew himself up at the base in Khost near the Pakistani border on December 30, killing seven agents and his Jordanian handler in the deadliest attack against the CIA since 1983.

According to the terror monitoring group SITE, 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.

These included Baitullah Mehsud, the leader of the Taleban in Pakistan, who is blamed for a series of deadly attacks including the killing of the former Prime Minister Benazir Bhutto in December 2007.

Mehsud was killed when a US missile struck his father-in-law’s house on August 5 last year.

Abu Saleh al-Somali, described as part of al-Qaeda’s core leadership, was also named. He was responsible for plotting attacks in Europe and the United States, and was killed in a drone strike in the North Waziristan area in December last year.

The al-Qaeda statement surfaced after another round of attacks by the remote-controlled aircraft that left 11 militants dead near Pakistan’s Afghan border on Wednesday, the first strikes since the CIA bombing.

The area is a stronghold of Hafiz Gul Bahadur, who fought with the Taleban when US-led troops invaded Afghanistan and is reputed to control up to 2,000 fighters whom he sends across the border but who do not attack in Pakistan.

Earlier the mother and wife of al-Balawi denied he was an extremist, while his brother said the “angry” father-of-two, whose family came from Palestine, had been radicalised by Israeli attacks on Gaza.

Before the bombing he was regarded as one of the CIA’s top assets.

Claiming she had not heard from him in 10 months, al-Balawi’s mother, Shanara Fadel al-Balawi, said: “We hear the news about my son … but I don’t know if he is dead or not.”

The 64-year-old added: “He prayed and read the Koran but was never an extremist. He never shared extremist views.”

Jihadist websites have claimed al-Balawi duped Western intelligence services for months before turning on his handlers.

The Jordanian intelligence services had taken al-Balawi to eastern Afghanistan to help track down Ayman al-Zawahiri, Osama bin Laden’s right-hand man.

Al-Balawi’s Palestinian family moved to Jordan after Iraq’s 1990 invasion of Kuwait.

“My son was conscientious. He was a good student at a Jordanian public school,” his mother said.

“He applied last year for an American visa to study in the United States, and even paid fees,” she added.

“He told us he was going to Turkey to get his original diploma, in late February. But we realised he never went then to Turkey,” she said.

Al-Balawi’s Turkish wife told the NTV news channel that she did not believe her husband worked for any intelligence agency.

“My husband definitely cannot be an agent for the CIA or Jordan because he was a man who would not even leave the house. I do not believe my husband could have done this,” Defne Bayrak said.

“He never told me of such a thing and I do not think that is the case.”

Ms Bayrak said that al-Balawi, whom she married nine years ago, did not go to Afghanistan, but instead travelled to Pakistan to pursue medical studies.

“He wanted to study to become a surgeon. We knew that he got himself a job when he could not sort out his study plans.

“We last spoke on the phone about one-and-a-half months ago. It was a normal conversation. He talked about coming to Turkey … He had told us to go to Turkey and that he would come soon,” she said.

According to al-Balawi’s mother, Ms Bayrak and her son met while he was studying medicine in Turkey. The couple have two children, Laila and Lina.

They also lived in Jordan for a while where al-Balawi worked in a hospital in a Palestinian refugee camp and his wife translated books from Arabic into Turkish.

One publishing house brought out a book authored by Ms Bayrak entitled Osama Bin Laden, the Che Guevara of the East.

The alleged bomber’s brother said he had been radicalised by the devastating offensive that Israel launched on Gaza in December 2008.

“The Israeli military operation in Gaza affected Humam and he wanted to join doctors of the Jordan Medical Association as a volunteer and go to Gaza,” said his brother, who would not be named.

“Humam was angry because of the crimes committed by Israel in Gaza,” he said.