KABUL - The government should urgently investigate High Peace Council chairman Prof. Burhanuddin Rabbani's assassination and bring the attackers to justice, a top opposition leader demanded on Thursday. The former president was killed in a suicide attack at his residence in the high-security area of Wazir Akbar Khan on Tuesday evening. He would be laid to rest at a hilltop in the diplomatic district on Friday.

Coalition for Change and Hope leader Dr. Abdullah Abdullah, President Hamid Karzai's arch political foe, asked the authorities to tell the nation who was behind killing the Jamiat-i-Islami leader.

Also on Thursday, the Afghan spy service -- known as the National Directorate of Security – alleged the Taliban's Quetta Shura was involved in the assault, which has drawn strong condemnation from Afghan leadership and the global fraternity.

Abdullah accused the government of failing to share with the nation the outcome of investigations into a string of assassinations of high-profile figures, including Syed Mustafa Kazimi, Gen. Daud Daud, Malik Zarin, Khan Mohammad, Abdul Rahman Syedkheli and Ahmad Wali Karzai.

At a news conference, the former foreign minister asked the rulers not to assign the Rabbani murder case to the backyard. The top peace negotiator's killing would not be the last political assassination in Afghanistan, he added.

He questioned President Karzai's directives to Rabbani to cut short his visit to Iran and meet the little known suicide bomber, disguised as a Taliban emissary with an important message. Such queries needed satisfactory answers from the government, he remarked.

The assault had resulted from the rulers' wrong policies, Abdullah said, without elaborating on what he called flawed politics. A government that could not maintain security with tens of thousands of foreign forces and foreign forces should stand down immediately, he added.

While urging an urgent review of the campaign for reconciliation with Afghan Taliban, he called for the Karzai administration to distinguish between Afghanistan's friends and enemies.