KABUL, Oct 31, 2009 (AFP) - Afghan authorities have arrested six people in connection with a deadly Taliban attack against a guesthouse for UN staff in the capital Kabul, the head of the national intelligence service said Saturday.

"Six people have been arrested and we have handed them over to the judicial authorities," Amrullah Salih told a press conference in Kabul.

Salih said it had been confirmed that three suicide attackers who carried out the attack at the Bekhtar Guesthouse on Wednesday were from Pakistan.

"All three bombers were from the Swat Valley," he said, referring to an area in Pakistan that has a reputation as a hotbed of militancy.

"The attack was a mixed Al-Qaeda and Taliban operation, and the Haqqani group also played an essential role," Salih said, referring to a militant group headed by Jalaluddin Haqqani which is blamed for a number of attacks in Kabul in recent years.

Taliban suicide gunmen stormed a UN hostel in Kabul early Wednesday morning, killing at least five foreign staff in an assault the Islamist militia said marked the start of a bloody countdown to new Afghan elections on November 7.