The head of Afghanistan's High Peace Council, former president Burhanuddin Rabbani, was killed by a Taliban suicide bomber at his home near the U.S. embassy in Kabul Tuesday night, dealing a serious blow to the prospects of reconciliation in the country.

Four aides also died in the attack, which one council member said was carried out by a trusted Taliban figure who detonated explosives hidden in his turban as he embraced Mr. Rabbani.