Rabbani, perhaps the most prominent Afghan to be killed since the fall of the Taleban in 2001. He died at his home early on Tuesday evening after a suicide bomber detonated explosives concealed in a turban.

The killing was a strong statement of Taleban opposition to peace talks, and the latest in a string of high-profile assassinations to shake the confidence of ordinary Afghans that security can be improved.

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.

His inner circle have not yet decided where to bury Rabbani, who first made his name as a fiery lecturer and activist and then became an anti-Soviet fighter, before briefly heading the country after the fall of the Soviet-backed regime.

“Discussions are still going on whether to bury professor Rabbani on the Wazir Akbar Khan hilltop, or the west of Kabul in the university,” Abdul Wali Niazi, a close aide to Rabbani, told Reuters.

Wazir Akbar Khan is Kabul’s diplomatic enclave, where Rabbani had his well-guarded home.

His killer was reported to have been escorted through layers of security without checks, because of promises he brought a message from the Taleban leadership.

On Wednesday morning, crowds gathered on the blocked-off street where Rabbani had his home, and armored cars with blacked-out windows carried senior officials, friends and other prominent Afghans to a memorial service inside.

Students from Kabul university carrying banners, angry at the government, were among the hundreds-strong crowd on a street draped with black banners.

“The situation will further deteriorate because of the killings of our leaders,” said Mujeed, a 21 year-old student of political law, from Rabbani’s home province of Badakhshan.

“We have no choice but to arm ourselves and defend the country. This is a plot hatched by the government to get rid of Rabbani, because he was exposing the fact that the government wanted the Taleban to come back,” he said.

A group of about nine other students clustered around him nodded in agreement.

Various activities planned to celebrate peace day across the city, including a concert for women by famous Afghan singer Farhad Darya, were canceled after the assassination.