Al Qaeda has released a statement saying four of its commanders in Afghanistan have been killed including top explosives and poisons expert Abu Khabab al-Masri.
The statement did not say how the four died, but Pakistani officials said they believe al-Masri was killed in an American air strike on a compound last Monday near the Afghan border.
The U.S. had posted a US$5 million reward for information leading to al-Masri's capture or death.
He was accused of training other terrorists to build bombs and use poisons. He is believed to have trained the suicide bomber who carried out the 2000 attack on the USS Cole in Yemen. Seventeen sailors died in that incident.
In its statement, published on a website frequently used by Islamist militants, al Qaeda said al-Masri's death will be avenged.
"We tell the enemies of God that God has saved those who will be even more painful for you ... (al-Masri) left behind, with God's grace, a generation of faithful students who will make you suffer the worst torture and avenge him and his brothers," the statement said.
Mustafa Abu al-Yazeed, al Qaeda's top leader in Afghanistan, signed the statement, which is dated July 30. It has not been independently authenticated.
Al Qaeda has long been linked with the Taliban, the local Pashtun Islamist militants who provided a safe haven for the global terrorist group when they ruled Afghanistan between 1996 and 2001. The U.S. led an effort to push the Taliban from power and attack al Qaeda in the wake of the Sept. 11, 2001 terror attacks on U.S. soil.
Some experts saw the hand of al Qaeda in the June attack on Sarposa prison in Kandahar City that freed hundreds of Taliban fighters. A massive truck bomb destroyed the prison's front gates. The co-ordination and planning involved in the attack seemed sophisticated by Taliban standards.
Al Qaeda is now believed to have a reasonably safe haven in the tribal areas of neighbouring Pakistan. Osama bin Laden and Ayman al-Zawahri, the group's top two leaders, are believed to be hiding in Pakistan. A Taliban leader in Pakistan denied reports that al-Zawahri had been grieviously wounded in a missile strike this past week.
Pakistan's tribal areas also provide a haven for Taliban fighters. The Pashtun tribe extends from Afghanistan into Pakistan, and they largely consider the Afghan-Pakistan border to be artificial.
With files from The Associated Press
