Ahmed Omar Abdul Rahman, son of the blind sheikh Omar Abdul Rahman, was killed Friday on the "frontlines" in Afghanistan, the Egyptian Islamic Group said, according to the SITE Intelligence Group based just outside Washington.
The elder Abdul Rahman -- convicted in 1993 for his role in the New York bombing, plotting to bomb other targets including the United Nations and a plan to assassinate Egypt's president -- is EIG's spiritual leader.
Attacks around the world have been carried out in his name in recent years. He is currently serving a life sentence in the United States.
The message posted by EIG on its website said the cleric had sent several of his sons to fight in Afghanistan against Soviet troops in the 1980s, and that Ahmed was only son who had remained to this day.
There were no confirmed reports of a drone attack Friday in Afghanistan that fit EIG's description, but Pakistani officials told AFP that a US drone strike had killed four militants in northwestern Pakistan's Waziristan district near the Afghan border.
Covert CIA drones are the chief US weapon against Taliban and Al-Qaeda militants, who use Pakistan's lawless tribal areas as launchpads for attacking US troops in Afghanistan and plotting attacks on the West.