THE CIA has backed the Pakistan Government's assertions that members of al-Qaeda and allies of a tribal leader were responsible for the assassination of former Pakistani prime minister Benazir Bhutto.
Al-Qaeda and Pakistani tribal leader Baitullah Mehsud are also responsible for a new wave of violence threatening the country's stability, CIA director Michael Hayden has told The Washington Post.
Mr Hayden said Ms Bhutto was killed by fighters allied with Mehsud, a tribal leader in northwestern Pakistan, with support from the al-Qaeda network.
Soon after Ms Bhutto's December 27 assassination at a political rally in the city of Rawalpindi, Pakistani officials released intercepted communications between Mehsud and his supporters in which the tribal leader praised the killing and, according to the officials, appeared to take credit for it, The Post reported.
Until now, US officials have been been cautious about publicly embracing Pakistan's assessment.
There is deep suspicion among many Pakistanis that the Government of President Pervez Musharraf - a close US ally in the fight against terrorism - had a role in the killing.
But Mr Hayden said: "This was done by that network around Baitullah Mehsud. We have no reason to question that."
He told The Post that the assassination was "part of an organised campaign" that has included suicide bombings and other attacks on Pakistani leaders.
"What you see is, I think, a change in the character of what's going on there," Mr Hayden said.
"You've got this nexus now that probably was always there in latency but is now active: a nexus between al-Qaeda and various extremist and separatist groups.
"It is clear that their intention is to continue to try to do harm to the Pakistani state as it currently exists."
Since she was killed, Ms Bhutto's family has perpetuated public scepticism about who was to blame, alleging a wide conspiracy involving Government officials.