A U.S. magistrate on Friday ordered held without bail a Libyan man accused of gathering information about American intelligence operatives and arranging for the military training of American dissidents in Libya.

The magistrate granted bail to five other defendants, among them Mousa Hawamda, a travel agency owner accused of involvement in an alleged Libyan plot to assassinate former White House counter-terrorism aide Oliver North.But the prosecution immediately appealed the bail for Hawamda, a naturalized American described by the FBI as a senior Libyan intelligence operative, and he was ordered held pending an appeals hearing early next week.

The six were among eight men arrested Wednesday on suspicion of a scheme to illegally use Libyan government funds to solicit support for Libya among American dissidents, including Indians and Black Muslims.

Friday's hearing before magistrate Leonie Brinkema was to determine whether the six would be freed on bond.

The bail set ranged from $250,000 for Hawamda to $10,000 for Manhal Ben Mohamed, a Moroccan who worked for Hawamda.

Another two defendants are being held in Denver, Colo. and Detroit.

Alvin M. Binder, a criminal lawyer from Mississippi who represented four of the defendants in court, said the case was "very political." Binder, a criminal lawyer who represented Atlanta child murderer Wayne Williams in 1982, said the prosecution had made "allegations with no concrete evidence."

F. Andrew Carroll, the lawyer representing Hawamda, called the prosecution's contention of a plot to kill a high government official "ludicrous."

U.S. Attorney Henry Hudson has refused to name the senior official targeted for assassination, but an administration source said Wednesday it was North, who played a key role in the 1986 U.S. retaliatory bombing of Libya.

Hudson told reporters after the detention hearing that "the case involves issues far beyond just a diversion of funds."