In what could be a major embarrassment to Islamabad, Afghan and NATO security forces have detained several men in Afghanistan who have admitted that financing and recruiting of potential suicide bombers is being done in Pakistan, a media report said on Tuesday.
"Every single bomber or improvised explosive devices in one way or another is linked to Pakistan," a senior Afghan intelligence official told the New York Times.
"Their reasons are to keep Afghanistan destabilised, to make us fail, and to keep us fragmented."
The would-be suicide bombers arrested recently, the Afghan intelligence official told the paper, emerge from two clear strands.
Some are linked to extremist groups that have long been set up and run by Pakistani intelligence as an arm of foreign policy toward rival governments in Afghanistan and India.
They are technically illegal and the government now says it has cracked down on them.
Others are allied with Afghan groups like the Taliban and the renegade militia commander Gulbuddin Hekmatyar, also a longtime protégé of Pakistani intelligence, who has now allied himself with the Taliban, Afghan and NATO officials told the paper.
The paper said a senior United States military official based in Afghanistan agreed for the most part.
"The strong belief is that recruiting, training and provision of technical equipment for IED's in the main takes place outside Afghanistan," he said. By IED's he meant suicide bombers as well, the paper said.
Shah said he and his cohort had planned to blow themselves up in four separate attacks in the capital.
That they failed was due partly to luck and partly to vigilance by Afghan and NATO security forces.
But their plot represented a clear escalation in the bombers' ambitions in Afghanistan, the Times said.
The Times said at first Shah denied that he intended to be a suicide bomber, but said he had gone to Afghanistan only to fight a jihad. "I was just thinking of fighting a jihad against the infidels," he said.
But later he admitted that he had intended to blow himself up in Kabul. He was vague about the target of his suicide mission.
After he was arrested, Shah said, he learned that one member of his group, whom he called Abdullah, succeeded in carrying out a suicide attack outside the Interior Ministry.
"They came here to be martyred," he said of his three companions, all Pakistanis, all around the same age, and all also from Karachi.
Like Shah, the Times quoted officials as saying, several other would-be bombers arrested recently have come from Pakistan or were run by commanders based there.
The paper said Shah and his companions had all studied at the same religious school, or madrasa, at Masjid-e-Noor, a mosque in Mansehra Colony, in northeastern Karachi.
The madrasa was run until recently by Maulavi Abdul Shakoor Khairpuri, who, Shah said, was a member of a banned jihadi group, Harkat-ul-Mujahedeen.