Hundreds of people on Monday mourned the death of a former high-ranking Taliban official who had reconciled with the Afghan government and was trying to bring peace to his homeland.

A gunman in a car assassinated Arsala Rahmani on Sunday, dealing a powerful blow to the fragile, U.S.-backed effort to negotiate a political resolution to the more than decade-long war.

It was the second killing of a prominent member of the government-appointed peace council set up to reach out to insurgents. In September 2011, former Afghan President Burhanuddin Rabbani, the counci's head, was assassinated in his Kabul home by a suicide bomber posing as a peace emissary from the Taliban.

A military honor guard carried Rahmani's coffin, covered in a black cloth with verses of the Quran embroidered on it in gold, to a cemetery in the Afghan capital. Wreaths of flowers bore a photograph of the slain negotiator.

"We are all so sad for his death," said Shahzada Shahid, another member of the peace council.

"Rahmani had no personal dispute with anyone who would want to kill him," Shahid said. "He was working for the peace process, security and unity of the Afghans. ... It's been a series of killings of our countrymen. Elders, religious leaders, politicians, teachers, engineers and even businessmen are the victims."

The Taliban denied responsibility for Rahmani's killing, although they had publicly threatened to target peace negotiators and others working with the government.

The targeting of negotiators may represent divisions in the movement over peace talks.

Fighting in Afghanistan has mostly been centered in the south and east, along the border with Pakistan, but has spread to the once-peaceful north in recent years.