Parvez Ahmed, the Florida chairman of the Council on American-Islamic Relations, and other local Arab-American leaders stood with FBI officials to demonstrate their cooperation in the search for Adnan El Shukrijumah, whose last known address is suburban Broward County.

Hector Pesquera, head of the FBI's South Florida office, said El Shukrijumah "has been identified by senior members of the al-Qaida organization as a very, very, very serious threat to the United States' interests, both here and abroad."

Senior federal law enforcement officials, speaking on condition of anonymity, said last week that they are trying to link El Shukrijumah to Jose Padilla, a former South Florida man arrested last year for allegedly plotting to detonate a radioactive bomb.

The names of both Padilla and El Shukrijumah — or perhaps one of his half-dozen aliases — surfaced in the intelligence collected after the March 1 capture in Pakistan of senior al-Qaida organizer Khalid Sheikh Mohammed.

Arab-American community members voiced their concern Monday that any proceedings against El Shukrijumah be conducted in public, unlike Padilla, whom the government wants to try in secret as an enemy combatant.

"We do not presuppose guilt or innocence on Adnan Shukrijumah," Ahmed said. "We ask for the assurances of the FBI and the U.S. Department of Justice that they will uphold Adnan Shukrijumah's human rights should he be apprehended, which includes his rights to due process."

Pesquera declined give greater detail about the reasons for the FBI's interest in locating El Shukrijumah or about his background. He would also not speculate what would happen to El Shukrijumah if he is apprehended.

"We need to locate him and then those issues will be sorted out later. Certainly not by anyone here," Pesquera said. Such a decision would likely be made at the highest levels of the U.S. Justice Department.