WASHINGTON — The apparent ties between the Nigerian man charged with plotting to blow up an airliner on Christmas Day and a radical American-born Yemeni imam have cast a spotlight on a world of charismatic clerics who wield their Internet celebrity to indoctrinate young Muslims with extremist ideology and recruit them for Al Qaeda, American officials and counterterrorism specialists said.

American military and law enforcement authorities said Thursday that the man accused in the bombing attempt, Umar Farouk Abdulmutallab, most likely had contacts with the cleric, Anwar al-Awlaki, whom investigators have also named as having exchanged e-mail messages with Maj. Nidal Malik Hasan, an American Army psychiatrist charged with killing 13 people in a shooting rampage in November at Fort Hood, Tex.

Speaking in eloquent, often colloquial, English, Mr. Awlaki and other Internet imams from the Middle East to Britain offer a televangelist’s persuasive message of faith, purpose and a way forward, for both the young and as yet uncommitted, as well as for the most devout worshipers ready to take the next step, to jihad, officials say.

“People across the spectrum of radicalism can gravitate to them, if they’re just dipping their toe in or they’re hard core,” said Jarret Brachman, author of “Global Jihadism: Theory and Practice” (Routledge, 2008) and a consultant to the United States government about terrorism. “The most important thing they do is take very complex ideological thoughts and make them simple, with clear guidelines on how to follow Islamic law.”

In an online posting in 2005 under the name “farouk1986,” Mr. Abdulmutallab referred to another radical Muslim cleric he listened to, a Jamaican-born preacher named Abdullah el-Faisal.

Mr. Faisal, who was deported from Britain in 2007, was convicted four years earlier for soliciting murder and inciting racial hatred in English- and Arabic-language tapes of speeches urging his followers to kill Hindus, Christians, Jews and Americans. He was later accused of influencing one of the attackers in the London bombings of July 2005.

These celebrity imams — in addition to their knowledge of the Koran and Islamic theology — offer in some cases an almost heroic flair because of their occasional brushes with the law. Among the examples are Abu Yahya al-Libi, a Libyan cleric, who escaped from prison in Afghanistan in 2005, and Mr. Faisal, who continued to preach online even after his arrest and deportation.

In his May 2005 online posting, Mr. Abdulmutallab wrote: “i thought once they are arrested, no one hears about them for life and the keys to their prison wards are thrown away. That’s what I heard sheikh faisal of UK say (he has also been arrested i heard).”

Mr. Abdulmutallab has now become somewhat of a hero, with his photograph posted on Web sites that feature announcements by these prominent clerics.

American and European authorities say some of these clerics, like Mr. Awlaki, offer something much more sinister than just guideposts to radical Islam: a pipeline to Al Qaeda operatives in places like Yemen and the lawless Pakistan tribal areas.

“Awlaki is, among other things, a talent spotter,” an American counterterrorism official said. “That’s part of his value to Al Qaeda. If people are drawn to him, he can pass them along to trainers and operational planners. Abdulmutallab was cannon fodder, a piece snapped into an operation.”

Sheikh Khalid bin Abdul Rahman al-Husainan of Kuwait, who is fast attracting a large following, mixes contemporary politics with talk of martyrdom.

“Obama, in the same way that you raised the slogan, ‘Yes We Can,’ I too have a slogan,” Mr. Husainan wrote in August 2009. “My slogan in this life — and memorize this slogan — is ‘Happiness is the day of my martyrdom.’ ”

Intelligence officials and Congressional aides briefed this week on the inquiry say investigators are still trying to determine the precise nature of any contacts between Mr. Abdulmutallab and Mr. Awlaki.

It is not clear what role, if any, Mr. Awlaki played in the airliner plot.

Marc Sageman, a former Central Intelligence Agency operations officer and Qaeda scholar, said the relationship between these celebrity imams and younger men like Major Hasan and perhaps Mr. Abdulmutallab was a two-way street.

“It is really young people seeking them out — the movement is from the bottom up,” Mr. Sageman said. “Just like you saw Major Hasan send 21 e-mails to al-Awlaki, who sends him two back. You have people seeking these guys and asking them for advice. What they provide is a justification for what these young kids want to do in the first place. There is an influence, but the direction is from the young people seeking folks out, as opposed to older guys recruiting them.”

Mr. Sageman cautioned about placing too much singular responsibility on leaders like Mr. Awlaki. He also said he had no independent evidence that Mr. Awlaki and Mr. Abdulmutallab were linked.

But Mr. Sageman is anxious to find out if that is the case.

“Young people have a mind of their own,” he said. “They are not robots, brainwashed. They are already radicalized. What they want in a sense is a validation of what they already believe. The religious leaders are lightning rods, because of the extreme statements. They form a community around them.”

Mr. Sageman also said that leaders like Mr. Awlaki were effectively reaching into the Western world for an obvious reason: they can speak and write well in English, resulting in a following in Britain particularly.

“English speakers hang out with English speakers,” he said.

Representative Peter Hoekstra of Michigan, the ranking Republican on the House Intelligence Committee who participated in a classified briefing on Wednesday about the investigation, said his suspicions that there was some link between Mr. Abdulmutallab and Mr. Awlaki were strengthened by what he had been told.

Mr. Hoekstra questioned why these apparent links were not figured out before the attempted airliner attack took place.

“You would think if you did a Google search on these different threads, it would bring these things together quickly,” he said. “There are organizations that deal with massive amounts of data in real time every day. Talk to MasterCard.”