By Hamid Shalizi
KABUL (Reuters) - Afghanistan's intelligence agency said on Saturday that it had handed Pakistan evidence that the Taliban's leadership plotted the recent assassination of ex-president and government peace envoy Burhanuddin Rabbani on Pakistani soil.
The interior minister, giving testimony in parliament, also said that a master-mind of the plot -- Hameedullah Akhondzada -- had been arrested. The minister said Pakistan's spy agency, the Directorate of Inter-Services Intelligence (ISI), played a role in the killing.
Rabbani, who was head of the High Peace Council charged with trying to reach a negotiated settlement to the war, was killed at his Kabul home by a suicide bomber claiming to be carrying a message of peace from the Taliban leadership.
"Without any doubt Pakistan's ISI hand has been involved," Interior Minister Bismillah Mohammadi told lawmakers on Saturday, while discussing Rabbani's killing.
"We have detained Hameedullah Akhondzada who confessed that it was nothing but a plot," he added.
Mohammadi said a fact-finding mission was leaving for Pakistan on Saturday to investigate further, and Islamabad had been given a list of those involved.
A spokeswoman for Pakistan's Foreign Office, Tehmina Janjua, said Pakistan had not received any information although Prime Minister Yusuf Raza Gilani had conveyed to Afghan President Hamid Karzai an offer of cooperation in the investigation.
"Pakistan's offer to investigate stands. As yet, no dossier has been received," she said.
Akhondzada has been named by the Afghanistan's National Directorate of Security (NDS) but it has given no details of his identity. Acting NDS chief Rahmatullah Nabeel also said that Akhondzada had been detained, but gave no details.
Rabbani was the most prominent surviving leader of the ethnic Tajik-dominated Northern Alliance of fighters and politicians and his killing was seen as a heavy blow to hopes of peace talks and has brought fears of worsening ethnic rifts among Afghans fighting the Taliban-led insurgency.
"PLOTTED IN QUETTA"
The NDS spokesman, at a separate news conference said that the mid-September suicide bombing that killed Rabbani, the government's top peace negotiator, was plotted in an upmarket suburb of the Pakistani city of Quetta.
The Taliban leadership council is known as the Quetta Shura, and is believed to be based in that city, although the insurgent group says it operates only from Afghanistan. Pakistan denies the existence of any Taliban shura in Quetta.
"A confession from those we detained in regard to Rabbani's assassination shows a direct involvement of the Quetta Shura," NDS spokesman Lutfullah Mashal said, adding that one of those arrested was a key player in the plot to kill Rabbani.
"(He) provided evidence and documents which we have submitted to the Pakistan Embassy. Based on mutual cooperation and diplomatic ties with Afghanistan, Pakistan is obliged to take action," he told a news conference in the Afghan capital.
Rabbani's assassination was plotted in Quetta's Satellite Town, an expensive area home to many officials and the city's elite, Mashal added.
He said a commission had been set up to investigate the killing, and further details would be given soon.
Hours after Rabbani was killed, a spokesman for the Taliban claimed responsibility for his death when talking to a Reuters reporter in Pakistan from an undisclosed location.
However, the spokesman later issued statements denying that he had made a claim of responsibility and said the Taliban were not willing to comment on Rabbani's assassination.
(Additional reporting by Mohammad Ibrahim; Writing by Emma Graham-Harrison; Editing by Robert Birsel)