Former Afghan President Burhanuddin Rabbani was killed by a suicide bomber on Tuesday in his home in the capital, the latest in a series of high-profile assassinations to rock the country in recent months.
Rabbani was the head of a government panel set up last year to try to begin negotiations with the Taliban, and his death was seen as a serious blow to those still-nascent efforts.
The bomber, who apparently had explosives concealed in his turban, entered Rabbani's home in an upscale Kabul neighborhood on the pretext of visiting him, said Gen. Mohammed Zaher, the head of criminal investigation for the Kabul police.
The powerful blast injured at least two other people, Zaher said, possibly including at least one other member of the High Peace Council, as the reconciliation body was known.
The Associated Press reported that four of Rabbani's bodyguards were also killed, but that could not be immediately confirmed.
Rabbani's death came a short time before President Obama and Afghan President Hamid Karzai met in New York on the sidelines of the U.N. General Assembly, their first face-to-face session since the American leader announced plans to reduce the number of U.S. troops in Afghanistan over the coming year.
"This will not deter us from continuing down the path we have started," said Karzai, seated beside Obama at a Manhattan hotel. Karzai planned to cut short his New York visit and return home.
Rabbani served as Afghan president in the early-to-mid 1990s, and was the head of government at the time of the Taliban takeover.
He was a Tajik, one of Afghanistan's largest ethnic groups. Although there was no immediate claim of responsibility from the Taliban or other insurgent groups, the killing is likely to heighten ethnic tensions. Most Taliban are Pashtuns, the country's largest ethnic group.
Afghanistan's political climate, always violent, has become much more so in recent months.
Karzai's younger half-brother, Ahmed Wali Karzai, was assassinated by a close family associate in July. A close Karzai aide, Jan Mohammed Khan, was killed that same month, as was the mayor of the southern city of Kandahar, Ghulam Haidar Hamidi.
Times staff writer Christi Parsons in New York contributed to this report.