By Mirwais Harooni and Hamid Shalizi
KABUL (Reuters) - A Taliban suicide bomber on Tuesday killed Burhanuddin Rabbani, former Afghan president and head of the government's peace council, a dramatic show of insurgent reach and a heavy blow to hopes of reaching a political end to the war.
The killing was a strong statement of Taliban opposition to peace talks, and as the latest in a string of high-profile assassinations will increase the apprehension of ordinary Afghans about their future as the insurgency gathers pace.
Since Rabbani was a prominent Tajik, his killing is also likely to exacerbate ethnic divides, which in themselves could do more to halt any peace process than the death of a man who while influential, had so far produced limited evidence of concrete steps toward negotiations.
"A Taliban member who went to Rabbani's house for peace talks detonated a bomb hidden in his turban," a statement by the Kabul police chief's office said.
A police source said Masoom Stanekzai, a senior adviser to President Hamid Karzai, was badly injured in the attack.
It was the highest profile assassination in Afghanistan since the younger half-brother of President Hamid Karzai, Ahmad Wali Karzai, was killed at his home in July by a highly trusted family security guard.
It also came just a week after a deadly 20-hour siege by militants in the fortified capital - an attack which underlined how hard it will be for the United States to hand over security to Afghan forces by 2014 so it can bring home its troops.
"The killing of Rabbani is a serious blow against President Karzai and the government's peace and reconciliations efforts. It also underscores the inability of the government to protect even the most prominent Afghan politicians," one diplomat said.
Taliban spokesman Zabihullah Mujahid said the Taliban claimed responsibility. The central leadership had appointed two "articulate and well-trained" fighters to build contacts with Rabbani.
"Both of them were frequently meeting him at his Kabul home and secured trust of Rabbani and his guards. They were telling Rabbani that they would soon bring senior Taliban leadership to the negotiating table with him," Mujahid told Reuters by phone from an undisclosed location.
The Taliban frequently exaggerate battlefield exploits, but Mujahid's statements seemed to broadly match other accounts of the assassination. Mujahid said the group had made similar plans for assassinating "more such people" in the near future.
U.S. President Barack Obama called the killing of Rabbani, head of Afghanistan's High Peace Council, a tragic loss but said work needed to continue to bring elements of Afghan society together to end years of violence.
The United States had said it was open to talks with the Taliban as a way of helping to reach a political settlement to the war. But preliminary contacts had yielded little and already diminishing hopes of these making any progress appear to have been dashed by Rabbani's assassination.
Commander of the International Security Assistance Force in Afghanistan, General John R. Allen, called the killing "another outrageous indicator that, regardless of what Taliban leadership outside the country say, they do not want peace, but rather war."
"WILL NOT DETER US"
President Karzai, at the start of talks with Obama on the sidelines of the U.N. General Assembly, said Rabbani's death "will not deter us" from continuing the quest for peace.
Karzai, meeting Obama for the first time since the U.S. president announced a troop drawdown plan earlier this year, planned to cut short his New York visit to return home.
"It is a tragic loss," Obama said with Karzai at his side. "It is going to be important to continue the efforts to bring all of the elements in Afghanistan society together to end the senseless cycle of violence," he said.
US military officials acknowledged that the Taliban had embraced spectacular attacks and assassinations as an increasingly important part of their overall campaign -- a fact Washington says is proof insurgents have failed on the battlefield -- but they said foreign commanders were not planning any major change in strategy.
"We know this is what the Taliban are doing. We've got to adjust and we're doing it," Admiral Mike Mullen, who steps down this month as chairman of the U.S. Joint Chiefs of Staff, told reporters. "We're aware that ... they seek to continue this, but I don't think today is the time or this is the moment to make any significant change," he said.
"The bottom line still remains that we are moving in the right direction," Defense Secretary Leon Panetta said. "We have made progress against the Taliban, and we can't let some of these sporadic events deter us."
Rabbani, a former leader of a powerful mujahideen party during the Soviet occupation of Afghanistan in the 1980s, was chosen last October by Karzai to head the High Peace Council.
He served as president in the 1990s when mujahideen factions waged war for control of the country after the Soviet withdrawal.
"I'd put Rabbani as one of the half dozen most senior Afghan figures," said Kate Clark at the Afghan Analysts Network. "His more recent jobs - MP and head of the Higher Peace Council - simply did not reflect his continuing influence, which was felt at the palace, in clerical and mujahedeen networks and as a northern leader."
For northern leaders already worried about the mainly Pashtun insurgents from southern and eastern Afghanistan being included in a political settlement, Rabbani's assassination, she said "is a further blow to their confidence that their interests will be protected in any deal making."
The assassination comes after a series of suicide bombings and other major attacks believed to be the work of the Haqqani network, a Taliban-allied insurgent faction based along the Afghanistan-Pakistan border which Washington says still has links to Pakistan's Inter-Services Intelligence (ISI) agency. Pakistan denies these links.
One analyst said the peace council had not been seen as effective and that Rabbani himself was viewed by many as an impediment to a deal because he was so loathed by the Taliban.
"But, his assassination might mean that the networks Rabbani led or influenced within Afghanistan .... may resist a deal with the Taliban even more," said Caroline Wadhams, a security expert at the Center for American Progress in Washington.
"It could make it that much more difficult to get greater buy-in from key Afghan leaders, who have been deeply skeptical of talks with the Taliban for some time."
Vali Nasr, a former senior official in the State Department's Afghanistan/Pakistan office, said: "The Taliban wants to send a very powerful message that the Karzai government is not in charge."
"That is important because people begin to waver and shift their allegiances ... And it makes it very difficult to say the Taliban is serious about negotiations if they keep killing people they should be negotiating with," Nasr said.
(Additional reporting by Emma Graham-Harrison in Kabul, Laura MacInnis in New York, and Missy Ryan in Washington, Writing by Jonathan Thatcher and Myra MacDonald)