By Mark Hosenball and David Ashenfelter
WASHINGTON/DETROIT, June 9 (Reuters) - A judge has ordered monitoring of computer and Internet use of a U.S. Islamic preacher regarded by some federal officials and a group that studies radicals as an inspirational figure for foreign fighters in Syria.
The close supervision was ordered on Ahmad Musa Jebril, 43, after a court hearing last Thursday at which he was deemed to have violated conditions of his early release from a lengthy prison sentence imposed for fraud and jury tampering.
In a written order he issued after the hearing in Detroit, Federal Judge Gerald Rosen did not link his decision to Jebril's online preaching.
But federal officials familiar with the case told Reuters the judge's order would allow probation authorities to monitor Jebril's activities to make sure he is not trying to instigate Americans to travel to Syria to join other foreign fighters. The officials spoke on condition of anonymity because they were discussing sensitive information.
Neither Jebril, who lives in Dearborn, Michigan, nor his defense lawyer would comment to Reuters at the court hearing or following the decision.
Other officials said U.S. authorities were stepping up efforts to track and investigate Americans who go to Syria to join rebels trying to oust President Bashar al-Assad, and estimated that several dozen Americans had done so.
Security authorities in some European countries, including Britain, Belgium, the Netherlands and Germany, say hundreds of their citizens have done likewise.
The Justice Department, the Federal Bureau of Investigation and U.S. spy agencies have recently assigned coordinators or special teams to monitor such travel, fearing that radicalized Americans may return and stage attacks at home.
This month, U.S. authorities said that a Florida man, Moner Mohammad Abu-salha, had become the first known American suicide bomber in Syria. Social media postings from purported militants indicated he carried out a suicide bombing in Idlib province on May 25 by Jabhat al-Nusra, an al Qaeda-affiliated group.
Federal probation authorities had said Jebril violated the terms of his early release by not informing them fully about a trip he made to North Carolina, when he failed to disclose that he was going to make speeches on Islamic topics.
Judge Rosen ordered Jebril not to travel outside eastern Michigan and to wear an electronic tracking device. He said Jebril must provide his probation officer with information about his computer systems and Internet services providers, as well as his passwords for such systems.
In April, a London think tank that specializes in studying radicals and violence described Jebril as one of two English-speaking "spiritual authorities" who were inspirational figures for foreigners fighting in Syria.
The International Centre for the Study of Radicalisation, a partnership of four academic institutions in London, the United States, Israel and Jordan, issued the finding in a report, which drew the attention of U.S. law enforcement officials.
The British study said that instead of directly urging English-speakers to join Syrian militants, Jebril "adopts the role of a cheerleader: supporting the principles of armed opposition to Assad, often in highly emotive terms, while employing extremely charged religious or sectarian idioms."
The study reported that several Britons who had traveled to Syria and fought with the Islamic State of Iraq and the Levant (ISIL), an extreme Sunni anti-Assad faction, had said watching Jebril's lectures on video had helped inspire them to join up.
U.S. officials in different agencies are divided over whether the rhetoric used by preachers like Jebril, often couched in religious imagery or symbolism, could violate U.S. law or is protected under free speech provisions of the First Amendment to the U.S. Constitution.
Jebril's website appeared on Monday to be unchanged from before the ruling. On Sunday he sent a tweet to a supporter of militant group ISIL, saying he was no longer able to use instant messaging service WhatsApp, but did not say why.
Jebril originally was jailed in 2005 for crimes committed with his father while running a string of rental properties. Prosecutors said they vandalized some of the properties and filed and collected on bogus insurance claims.
Documents filed in court by the government in the sentencing phase of Jebril's trial alleged that he and his father had a long involvement with Islamic militant groups and ideology.
They said that Jebril ran an anti-American Islamist website called AlSalafyoon.doc. Prosecutors said the site included a "library of fanatically anti-American sermons by militant Islamic clerics ..." (Additional reporting by Cherie Curry in Detroit; Editing by David Storey, Martin Howell, Lisa Shumaker and Bernard Orr)