Pakistan's powerful intelligence agency communicated with Afghan insurgents who attacked the U.S. Embassy and NATO headquarters in central Kabul last week and appear to have provided them with equipment, according to U.S. military officers and former officials.
Communications gear used by the insurgents "implicated" the directorate for Inter-Services Intelligence, or ISI, Pakistan's spy service, a senior U.S. military official said Thursday. The equipment was found in a
14-story building under construction that the attackers used to lay siege to the embassy compound for 19 hours on Sept. 13, according to the official, who would not describe the equipment recovered.
Bruce Riedel, a former White House advisor on Pakistan and a retired senior CIA official, said administration officials told him that "very firm intelligence" linked the Pakistani spy agency to the embassy attack, which killed at least nine Afghans.
"There are [communications] intercepts and the attackers were in cellphone contact back to Pakistan," he said.
In a dramatic appearance before the Senate Armed Services Committee, Adm. Michael G. Mullen, chairman of the Joint Chiefs of Staff, charged that the insurgents had received "ISI support" not only for the attack on America's most prominent diplomatic and military symbols in the Afghan capital, but also for a massive truck bomb assault this month on a U.S. combat outpost in Wardak province west of Kabul that wounded 77 U.S. soldiers.
Pakistan's government angrily denied any involvement. But Mullen's comments are the most direct, and most explosive, accusations by a senior U.S. official of direct complicity by Pakistan's chief intelligence agency in attacks on American facilities and military personnel.
The accusation brought to mind the 2008 terrorist attack in Mumbai, India, in which 10 gunmen killed 166 people, including six Americans. Communications intercepts and other evidence found afterward indicated that the militants took orders from Pakistani authorities during the attack.
If evidence confirms Pakistan's role in the latest attacks, it could imperil the already tense relations between Washington and Islamabad.
Those ties plummeted after Navy SEALs secretly flew into the Pakistani military garrison city of Abbottabad in early May to kill Osama bin Laden, infuriating many Pakistanis, who regarded it as a violation of their country's sovereignty.
Pakistan's intelligence service has a long history of using proxy groups to wage war in Afghanistan, in India and in Indian-controlled Kashmir, part of a disputed border region.
U.S. officials charge that the ISI maintains close links to the militant Haqqani network.
The Taliban-allied group uses Pakistan's northwest tribal region to launch cross-border attacks on U.S. and Afghan government forces.
U.S. officials say the attacks in Kabul and Wardak, as well as a June 28 assault on the Inter-Continental Hotel in Kabul, which killed at least 20 people, were carried out by Haqqani operatives. In the latter case, suicide bombers stormed the hotel, set off explosions and exchanged gunfire with Afghan security forces for hours.
U.S. officials have argued before that Haqqani leaders have ties to the ISI, but have never been as explicit as they were Thursday.
In his testimony, Mullen said "the Haqqani network acts as a veritable arm of Pakistan's Inter-Services Intelligence agency." In a news conference this week, he referred to the Haqqani group as a "proxy" for Pakistani intelligence.
Asked at a news conference in Islamabad, the Pakistani capital, about Mullen's charge, Foreign Ministry spokeswoman Tehmina Janjua tersely answered, "I would say a categoric no."
Interior Minister Rehman Malik also rejected allegations this week of ties between Pakistan's intelligence community and the Haqqani network.
Mullen is retiring next week, and he may feel more free than in the past to level such a volatile charge in public. He has met repeatedly with Gen. Ashfaq Kayani, chief of Pakistan's armed forces, and has long argued that Kayani was moving too slowly to address the threat from militants in the tribal areas along the border with Afghanistan.
U.S. officials have repeatedly pressed Pakistan to launch a military offensive to uproot Haqqani network fighters from their sanctuary in the rugged North Waziristan tribal region.
Pakistani military leaders have fended off those demands, arguing that their army is overstretched as it fights militants in other tribal areas who view the Pakistani government as their primary enemy. Haqqani network fighters have never directed any attacks against Pakistan.
Experts say Pakistan's intelligence community views the Haqqani group as a valuable hedge against Indian influence in Afghanistan after U.S. forces withdraw.
Both Mullen and Defense Secretary Leon E. Panetta, who also testified at the Senate hearing Thursday, argued that a break in relations with nuclear-armed Pakistan would be catastrophic.
The Obama administration needs Pakistan's cooperation to help end the decade-old war against the Taliban in Afghanistan, a priority for the White House. The CIA has conducted dozens of drone strikes against suspected Al Qaeda members and other militants in Pakistan, and the country provides a vital supply route for military forces in Afghanistan.
In his testimony, Panetta said he had warned Pakistani officials to sever their ties to the Haqqani insurgents and to stop them from launching attacks on U.S. forces in Afghanistan.
"I've made very clear that we will do everything necessary to protect our forces," he said. "I haven't spelled that out for them, but I would be very surprised if they were surprised by what we did to fulfill that commitment."
Several lawmakers at Thursday's hearing questioned whether the U.S. should add strict new conditions on its annual assistance to Pakistan or cut off aid entirely because of the ISI's suspected relationship with the Haqqani group and Taliban insurgents.
Pakistan receives about $3.5 billion in U.S. economic and military aid each year to help revamp critical infrastructure and to battle its homegrown militancy.
Cloud and Dilanian reported from Washington, Rodriguez from Islamabad.