Washington: Ayman al-Zawahiri, who is likely to be al-Qaeda’s new chief, is unpopular among other leaders of the terrorist outfit and his promotion may result in a bitter fight in the organisation, a senior US official said.

"Al-Zawahiri is obviously the presumed successor, but there are strong indications that he is not popular within certain circles of the group," a senior US intelligence official said, adding that it is an open question as to who will take over from Osama bin Laden.

"It is of course an anathema for al-Qaeda to hold free and fair elections, but if such elections were held, Zawahiri would most likely have a fight on his hands," he said.

The official said some members of al-Qaeda believed that Zawahiri is extremely controlling, is a macro manager and is not especially charismatic.

Laden was killed by US special forces near the Pakistan Military Academy in the garrison city of Abbottabad on May 2.

Soon after the killing of bin Laden, US officials said the al-Qaeda number two, al-Zawahiri, would have difficulties in maintaining the loyalty of bin Laden's large followers.

"As the only al-Qaeda leader whose authority was universally respected, bin Laden also maintained his cohesion, while Zawahiri is not as well respected within the outfit. He probably will have difficulty maintaining the loyalty of bin Laden's largely Gulf Arab followers," the official said.

59-year-old Zawahiri, an Egyptian Islamic theologian, was longtime deputy of bin Laden. He was the second and last "emir" of the Egyptian Islamic Jihad, an affiliate of al-Qaeda.

He said, it is most fitting that bin Laden's death comes at a time of great movement towards freedom and democracy that is sweeping the Arab world.