Midhat Mursi al-Sayid Umar, Weapons Expert and Trainer
Nationality: Egyptian

Known by the nickname Abu Khabab, the 54-year-old served as a trainer at al-Qaeda's Derunta camp in Afghanistan when it was set up in the late 1990s. There, he oversaw Project al-Zabadi, or "curdled milk," al-Qaeda's research program into chemical and biological weapons.

While at Derunta, Umar authored training manuals on how to make toxic weapons, and conducted a variety of experiments, including exposing dogs to cyanide. He was an expert on conventional explosives and taught courses on their use as well. Copies of his training manuals were recovered by the U.S. military after the invasion of Afghanistan in 2001.

Umar grew up in northern Egypt and graduated from Alexandria University in 1975 with a science degree. He served time in prison in the early 1980s as one of hundreds of people charged with conspiracy in the assassination of Egyptian President Anwar Sadat in 1981.

He left Egypt to fight the Soviets in Afghanistan in the late 1980s and was injured in 1988 in an explosion while experimenting with chemicals, said Omar Rushdi, an Egyptian political exile who knew Abu Khabab from those days.

"He was my neighbor," Rushdi said in an interview in Birmingham, England. "They used him for training because he's a chemist and had good experience with industrial explosives."

Rushdi said the bombmaker was slow to join al-Qaeda and not a close personal ally of his fellow Egyptian, Ayman al-Zawahiri, because he disagreed with the group's strategy and "didn't want to join the project against America." Rushdi suggested that Umar changed his mind and agreed to lead Project al-Zabadi in part because he needed money, and al-Qaeda was willing to pay for his services.

"If Abu Khabab had other choices, he wouldn't be with al-Qaeda," Rushdi said.

Under its Rewards for Justice Program, the U.S. government has posted a $5 million reward for information leading to the arrest or capture of Umar. "He's a trainer," a senior U.S. intelligence official said. "We haven't seen him in a leadership position, or calling the shots."

Shortly after a U.S. missile attack on a house in the Pakistani village of Damadola in January 2006, Pakistani officials reported that Umar had been killed in the strike. DNA tests later determined that he was not among the dead.

The U.S. reward notice for his capture says he "may be residing in Pakistan," although other reports have suggested he escaped to the Pankisi Gorge in the Caucasus region after the U.S. invasion of Afghanistan in 2001.

— Craig Whitlock and Munir Ladaa

© 2006 The Washington Post Company