According to a U.S. intelligence official, the CIA thinks that members of al-Qaeda and the Pakistani Taliban leader Baitullah Mahsud along with his allies are responsible for the assassination from last month of former Pakistani Prime Minister Benazir Bhutto.

The official said: "There are strong indications that Baitullah Mahsud was behind the Bhutto assassination. There is certainly no reason to doubt that Mahsud was behind this," Los Angeles Times reports.

CIA’s director, Michael V. Hayden, asserted that Bhutto was assassinated by Mehsud and his allies. This assertion is similar with the one expressed by the Pakistani government.

Hayden said in an interview with the Washington Post that the alliance between international and local terrorists means a risk for the government of President Pervez Musharraf.

He said: “What you see is, I think, a change in the character of what's going on there. 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.”

After Bhutto’s assassination in Rawalpindi, an intercepted telephone call was released by the Pakistani officials in which Mehsud congratulates a cleric for carrying the assassination.

Neither Pakistani, nor the U.S officials, has commented upon this matter.

Pakistani people suspect the government for the killing of Bhutto and even her family has issued a theory about a conspiracy including officials from the government.

Hayden refused to say what made CIA to reach the conclusion about Bhutto’s killer.

Hayden said: "This was done by that network around Baitullah Mehsud. We have no reason to question that," Washington Post said.

He also said that the assassination was part “of an organized campaign” that includes suicide bombings and attacks on other Pakistani leaders.

Hassan Abbas, who was an official during Bhutto’s administration and author of the book “Pakistan's Drift into Extremism: Allah, the Army and America's War on Terror," said that even if Mahsud was really involved in her assassination, it doesn’t mean that people from the Pakistani army and intelligence agency didn’t play a part too.

He said: “My view is that this was a combination of elements from the intelligence agencies with people from the extremist groups with whom they have working relationships.”