Swedish investigators have said they are looking for links between suspect Kerim Chatty and terror groups.
The FBI on Saturday visited a South Carolina flight school that Chatty briefly attended, the school's director Robert Sunday said. Chatty was accepted into the school in Conway, S.C., in September 1996 but flunked out a few months later, Sunday said.
"He was a very substandard student," said James Lamb, assistant chief flight instructor with the North American Institute of Aviation in Conway.
Meanwhile, the suspect's lawyer said his client, who denies any intention to seize a plane, converted to Islam after he attended the flight school.
Chatty, 29, was arrested Thursday with a gun in his carry-on luggage at a Swedish airport as he headed to an Islamic conference in Birmingham, England. He faces possible charges of planning to hijack a plane and illegal possession of a firearm.
A court hearing Monday will determine if formal charges should be filed and whether the suspect should be held as the investigation continues, Police spokesman Ulf Palm said.
At the hearing in Vasteras, prosecutors will lay out the case on which they plan to lay charges. The court will then be cleared as the judge hears from the suspect and his lawyer, and will decide whether to remand Chatty for further investigations, police spokesman Palm said.
Prosecutors then have a further two weeks to finalize their case. Palm said Chatty would probably be charged with planning a hijack or illegal possession of firearms and possibly further charges. He could face life imprisonment if found guilty.
Chatty was not being questioned by police on Sunday but was meeting his lawyer, Palm said.
Swedish investigators did not believe Chatty or any possible accomplices were connected to al Qaeda, the sources said. Instead they believe a copycat attack was being planned.
"There is nothing to suggest that this is al Qaeda," one Sapo police source told Reuters. "It's more likely that they are some kind of 'wannabes'."
Still, officials were not taking any chances. Palm said investigators were in contact with "foreign authorities." He declined to give more details or comment further about a possible motive.
"We hope to reveal more information during next week," Palm said. "Now the investigation is in a hectic stage."
Margareta Linderoth, the director of the national security police, said Saturday that officials were looking for any links between Chatty and terrorist groups. But she said that was not the only line of investigation.
Swedish intelligence and security police sources told Reuters four other men, including an explosives expert, were being sought in connection with the incident at Vasteras airport, a claim Linderoth denied.
"I have never heard that the man has planned to do what you say he has," she told Reuters. "We are not looking for four other men."
One security police source said the government had instructed the agency to play down the incident, which comes at a sensitive time for Sweden, two weeks before a general election on September 15. Highlighting the gravity of the incident, the Swedish government briefed opposition leaders on Saturday.
Defense lawyer Nils Uggla said Chatty, whose father is from Tunisia and mother is from Sweden, converted to Islam "three or four years ago" — after attending flight school. He confirmed Chatty was heading to the Birmingham Islamic conference as police have said.
At least three of the hijackers involved in the Sept. 11 attacks attended or visited flight schools in the United States.
The British tabloid The Mail on Sunday quoted Chatty's parents as saying their son's interest in Islam deepened after he met a group of Muslims at the U.S. flight school.
They told the newspaper that he was "studying at a Muslim school" in Saudi Arabia at the time of the Sept. 11 attacks.
"I cannot understand why he had that gun with him. I know it must be a mistake. He would never have hijacked that plane," his mother, Gunilla, was quoted as saying.
Uggla has said Chatty has an explanation for why he had the gun in his toiletries bag as he boarded a Ryanair flight to London at Vaesteraas airport, 60 miles northwest of Stockholm. Uggla said he could not elaborate because of a gag order.
The Swedish tabloid Aftonbladet said Chatty was questioned in Sweden about contacts with radical Muslim groups after the Sept. 11 attacks. The information could not immediately be confirmed.