KABUL (Reuters) - Afghanistan's intelligence agency said on Monday it had arrested a key figure in last week's assassination of ex-President Burhanuddin Rabbani and suggested the Taliban's senior leadership may have been involved.
The National Directorate of Security (NDS) said an Afghan suspect had revealed that last Tuesday's suicide bombing that killed Rabbani, the government's top peace negotiator, was plotted outside the country.
"Now finally we know from whom and where the plot originated, how it was carried out and in a very short time, we will give the details to our people," said Zeya, deputy head of the NDS, who like many Afghans goes by only one name.
He told a hastily arranged news conference late on Monday that he would not identify the arrested man to avoid jeopardizing the investigation.
Rabbani, who became president soon after the fall of the Soviet-backed government during the early 1990s, was killed at his Kabul home by a suicide bomber claiming to be carrying a message of peace from the Taliban leadership.
He was the most prominent surviving leader of the ethnic Tajik-dominated Northern Alliance of fighters and politicians and his killing has brought fears of worsening ethnic rifts among Afghans fighting the Taliban-led insurgency.
Supporters of Rabbani planned to hold a march through Kabul early on Tuesday to condemn the assassination of the former mujahedeen fighter.
Zeya suggested the Quetta Shura, the Taliban's leadership council, may have played a role in Rabbani's killing and said the NDS would recommend to President Hamid Karzai that he push for the investigation to be taken beyond Afghanistan's borders.
"I don't deny Quetta Shura's involvement in this case," he said, without elaborating. "We will have a meeting with the Afghan president and there we will suggest that this case be investigated outside Afghanistan."
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.
(Reporting by Mirwais Harooni; Writing by Martin Petty; Editing by Emma Graham-Harrison)