A senior international official involved in international counterterrorism efforts said there was information indicating that al-Qaeda leader Ayman al-Zawahiri had a "heart complaint." The official told CNN that the information indicated that al-Zawahiri had a serious illness, The difficulty of ascertaining the seriousness of his health problems and the impact he may have on the length of his life.

The official explained that the prospect of Zawahiri, 68, suffering from a serious illness "increases the uncertainty about plans for the long-term leadership succession of al-Qaeda."

Osama bin Laden's son, Hamza bin Laden, was expected to take command of the organization, but an American official told CNN on Wednesday that the United States now believed he had died.

Al-Zawahri's health was also mentioned in a UN monitoring report, which was distributed this summer to the Security Council. Quoting "member state information".

Zawahiri said he was "in poor health," and said that although al-Qaeda was still "resilient", "the health and longevity of its leader, and how the caliphate would be in doubt."

Zawahri continued to appear frequently in al-Qaeda videos, the last of which was last month, while there were no clear signs that he was seriously ill in these videos. "

A US official who tracks the organization told CNN earlier this year that "the command and control of the group is flexible, active and able to respond."

The US official said the United States had a role in the death of Hamzah bin Laden, but gave no details. The official said the US government had recently received evidence that it believed it confirmed his death.

The New York Times reported that Hamza bin Laden had been killed in an operation over the past two years, and the United States offered a reward of $ 1 million in February to obtain information about his whereabouts.

The last appearance of bin Laden was on 31 March 2018. According to a senior official involved in international counterterrorism efforts, there is information that Hamza bin Laden was recently residing in the border area between Afghanistan and Pakistan, met with Zawahiri there during the past two years, That the intelligence picture of bin Laden's movements was fragmentary and inaccurate.

Counterterrorism experts believe Egyptian terrorists Abu Mohammed al-Masri and Saif al-Adl are likely to take over from Zawahri, both wanted for the al-Qaeda bombings of two US embassies in East Africa in 1998.