KABUL (Reuters) - Afghan security officials said on Saturday they had arrested six militants linked to the Taliban and al Qaeda over an attack on a Kabul guest-house in which five foreign U.N. staff were killed.
The Taliban claimed responsibility for Wednesday's attack on the guest-house, saying it was launched because of the United Nations' role in helping organize next week's presidential run-off vote.
The Islamist militants have vowed to disrupt the vote.
Afghanistan's intelligence chief, Amrullah Saleh, said the attack had been "orchestrated" by the Haqqani network, one of the main al Qaeda-linked groups battling U.S. and other foreign forces in Afghanistan.
He said the ringleader of the group, who drove the attackers to the guest-house, was arrested by Saudi officials at the Medina airport in Saudi Arabia after information gathered during the interrogation of other suspects arrested in Afghanistan.
The man had since been returned to Afghanistan, he said.
Three suicide bombers blew themselves up during the attack on the guest-house.
"The confession of those arrested show that the suicide bombers who carried out the attacks were from the Swat valley of Pakistan," Saleh told a news conference.
Four others remained at large, he said.
Pakistan is fighting its own Taliban insurgency and the military there launched a campaign in the Swat valley northwest of Islamabad near the Afghan border in April.
The Haqqani network has long links with Pakistan, with a house once owned by a relative of Haqqani hit in a U.S. missile strike in September.
The group's spiritual leader is Jalaluddin Haqqani, a veteran Afghan militant commander and senior Taliban leader.
Haqqani, known in the past to have been close to al Qaeda leader Osama bin Laden, is said to be in poor health and the group is now led by his son, Sirajuddin.
(Reporting by Hamid Shalizi; Editing by Paul Tait)
Afghanistan authorities said on Saturday that they have arrested at least six people believed to have been involved in Wednesday's deadly attack on a United Nations guesthouse in Kabul. Afghan intelligence chief Amrullah Saleh announced the arrests on Saturday.

The assault, lead by militants linked to the Taliban and al-Qaeda, killed five foreign UN employees and at least two Afghan guards. The three attackers also were killed. The Taliban said the attack was the first step in a plan to disrupt Afghanistan's November 7 presidential runoff election.

Militants stormed the UN residence around dawn wearing suicide vests. UN security officers battled them for at least an hour before NATO troops and Afghan police showed up.

UN officials have called for a strengthening of security measures after the incident.