The Egyptian who guards the elusive Osama bin Laden has taken over as Al Qaeda’s military commander following capture of Khalid Sheikh Mohammed, the 9/11 mastermind, a terror expert said on Monday. Saif al-Adel, who is believed to have turned 40 last month, has a $25 million price on his head on the FBI’s list of most wanted terrorists. The United States had indicted him over the 1998 bombings of the US embassies in Kenya and Tanzania. Al Qaeda turned to Al-Adel after Mohammed’s arrest in Pakistan in March removed the military commander whose careful years of planning resulted in the 9/11 strikes, said Rohan Gunaratna, author of Inside Al Qaeda: Global Network of Terror. ‘‘They chose him because he is their most competent man and he fits into the typical Al Qaeda, Islamic jihad mindset,’’ said Gunaratna, now based in Singapore. Al-Adel has shown ruthless efficiency in his role as chief of Al Qaeda’s security and above all in protecting Laden, the world’s most wanted man, said Gunaratna. As a highly structured organisation, he said, Al Qaeda would have made a point of formally appointing a successor to Mohammed. Al-Adel may bring a different style to future attacks. ‘‘They will become much more secretive, much more discreet, they will learn from mistakes of the past,’’ said Gunaratna. Al Qaeda’s reputation for secrecy will be further enhanced, he said. Al-Adel’s photo on the FBI’s most wanted list shows a clean-shaven, narrow-faced man. He is believed, like Laden, to be hiding along the porous Pakistan-Afghanistan border. His responsibilities at the heart of Al Qaeda have involved registration and screening of new members, developing communications systems and above all protecting his chief. ‘‘He has to be given credit for the survival of Laden.’’ ‘‘The current spate of operations were planned and prepared by Khalid Sheikh Mohammed and by Tawfiq bin Attash,’’ he said of last week’s strikes in Riyadh, Saudi Arabia that killed 34 including 15 suicide bombers and the weekend attacks in Casablanca, that killed 41, including 13 suicide bombers. Attash, a one-legged former bodyguard to Laden, was arrested in Pakistan this month. (Reuters)