The son of a Saudi Arabian imam, Adnan Shukrijumah, al-Qaeda's new head of "global operational planning", is using his unprecedented knowledge of American society to plot attacks against the United States and other Western countries, according to the FBI.

Shukrijumah came to the US with his patents as a young child and lived in New York and Florida. He assumed his new role in the terror group after two colleagues on an "executive operations council'' were killedbysuspectedUSdrone attacks, theFBIsaid.

Investigators believe that Shukrijumah, 35, is "extremely dangerous" in part because of the experience he can draw on having lived in the US for 15years,TheTelegraph reports.

Shukrijumah has taken over a position once held by Khalid Sheikh Mohammed, the mastermind of the September 11 World Trade Center

attacks, who was captured in2003.

His role puts him in regular contact with al-Qaeda's senior leadership, including Osama bin Laden, accordingto an FBIagent,thepapersays.

"He's making operational decisions the best way to put it He's looking at attacking the US and other Western countries," said Brian LeBlanc, a Miami-based counter-terrorism agent.

"He knows how the system works. He knows how to get a driver's licence, he knows how to get a passport. He out there plotting the attacks and recruiting people," he added.

Shukrijumah is also suspected of playing a role in plots against the London Underground and in Norway that never came to fruition.

The suspect's mother, Zurah Adbu Ahmed, who still lives in south Florida, said the authorities were using her son as a scapegoat. She said she had not spoken to her son since the September 11 attacks,TheTelegraph reports.