The weekend suicide bombing of a NATO convoy that killed 17 people in Kabul adds urgency to the U.S.-led coalition's work to expand a security bubble around the Afghan capital.
With most of the attacks in Kabul blamed on the Pakistan-based Haqqani network, the latest reinforced U.S. and Afghan demands that Islamabad do more to curb militant activity and sanctuaries on its territory.
While there is no specific information linking Saturday's convoy attack to the Haqqani network, investigators say they soon will have evidence the bombing was "Haqqani-related," a western diplomat said Sunday. The diplomat, who spoke on condition of anonymity to discuss the investigation, said it was "very possible" the attack was the work of Haqqani fighters, who have ties to both al-Qaida and the Taliban.
In the brazen midday assault, a suicide bomber rammed a vehicle packed with explosives into an armored coalition bus traveling in the southwest end of the city. Heavily armored military vehicles also were in the convoy, but the bomber targeted the bus, which was carrying troops and civilians contractors.
The Haqqanis were the specific focus of two military operations this month that involved tens of thousands of Afghan and NATO troops. They were conducted over nine days in Kabul province, Wardak, Logar and Ghazni provinces south and west of the capital and Paktia, Paktika and Khost provinces along the border. More than 200 insurgents were killed or captured. At least 20 of them had ties to the Haqqani group, including 10 identified as leaders of the network.
Marine Gen. John Allen, the top commander of U.S. and NATO forces in Afghanistan, said in a recent interview with The Associated Press that the operations against the Haqqanis were conducted in preparation for next year's plan to step up operations to keep insurgents from infiltrating across the Pakistani border and into the capital, especially from the south.
"The campaign plan is to extend operations down in that area _ pretty significantly _ to secure the orbital districts around Kabul and push that security zone out," Allen said.
"The overarching campaign plan for next year is going to see us consolidate our holdings in the south, conduct operations in the east to expand the security zone around Kabul and then connect the two," he said. That also would facilitate travel along a highway that connecting Kabul with southern Afghanistan, he said.
In Saturday's attack, the force of the explosion knocked the bus on its side and ignited a large fire that sent heavy black smoke rising above the scene. Seventeen people died _ five NATO service members, including one Canadian soldier; eight civilian contractors, including two from Britain; and four Afghans, including a policeman.
A U.S. defense official initially said all the foreigners killed were American, but that could not be confirmed. NATO does not disclose the nationalities of those killed.
Fluor Corp., a company based in Irving, Texas, that employs contractors in Afghanistan, confirmed on Sunday that some of its employees, including the two British nationals, were killed in the attack. Their names were not being released out of respect for their families, said Keith Stephens, a company representative.
The deadly attack was on a thoroughfare near the landmark Darulaman Palace, the bombed-out seat of former Afghan kings. At the time of the blast, Afghan lawmakers and ministers were gathered at the parliament building nearby to remember six lawmakers killed in a 2007 suicide bombing in Baghlan province. A lawmaker from Kunar province, who was making a speech, ducked when he heard the loud explosion.
At least 11 of about 15 major attacks in the capital this year can be blamed on the Haqqanis, according to a senior official with the coalition who spoke on condition of anonymity to discuss undisclosed investigative reports on the incidents.
Last month, then-Joint Chiefs of Staff Chairman Adm. Mike Mullen said the Haqqani network "acts as a veritable arm" of Pakistan's intelligence agency _ an accusation that Pakistan has denied.
Mullen accused the network of staging an attack against the U.S. Embassy and NATO headquarters in Kabul on Sept. 13 as well as a truck bombing that wounded 77 American soldiers in Wardak province. He claimed Pakistan's spy agency helped the group.
The senior coalition official said that the Taliban, based in the Pakistani city of Quetta, appeared to linked to the Sept. 20 assassination of former Afghan President Burhanuddin Rabbani, but that investigators did not see any direct tie to the Pakistani intelligence service. Rabbani, who was leading the Afghan government's effort to broker peace with the Taliban, was killed at his Kabul home by an assassin posing as a peace emissary from the insurgent group.
The United States has stepped up criticism of Pakistan and its counterterrorism cooperation but at the same time has worked to cajole the increasingly angry and resistant Pakistanis into doing more to squeeze militants on its side of the border.
U.S. Secretary of State Hillary Rodham Clinton delivered an unusually blunt warning to the Pakistanis when she visited the region last week. She said Pakistan "must be part of the solution" to the Afghan conflict. Clinton said the Obama administration expects the Pakistani government, military and intelligence services to "take the lead" in not only fighting insurgents based in Pakistan but also in encouraging Afghan militants to reconcile with Afghan society.
U.S. Army Lt. Gen. Curtis Scaparrotti, who directs day-to-day military operations in Afghanistan, said this week that he thinks the goal to have Afghan security forces in the lead across the country by the end of 2014 can be achieved without work against militant sanctuaries in Pakistan. But he said it would be a challenge.
"In order to do that, we have to build a strong, capable layered defense with the Afghan national security forces in order to provide, you know, a proper interdiction. And that it'll be a much tougher task, he said.
Associated Press writers Tarek El-Tablawy and Rahim Faiez in Kabul contributed to this report.