NEW YORK - The FBI is trying to ferret out possible Hizbollah agents in the United States amid concerns that rising U.S.-Iranian tensions could trigger attacks on American soil, FBI officials said.

Relations between Washington and Tehran, which soured after the 1979 Islamic revolution, have deteriorated further recently over Iran's nuclear program and its support for Hizbollah, the militant Islamic group whose capture of two Israeli soldiers last week prompted Israel to launch retaliatory strikes in Lebanon.

American law enforcement officials are concerned the Lebanon-based Hizbollah, which has so far focused on fund-raising and other support activities inside the United States, could turn to violence in solidarity with Iran.

"If the situation escalates, will Hizbollah take the gloves off, so to speak, and attack here in the United States, which they've been reluctant to do until now?" said William Kowalski, assistant special agent in charge of the FBI in Detroit.

Detroit is home to one of the largest Muslim communities in the United States.

"Because of the heightened difficulties surrounding U.S.-Iranian relations, the FBI has increased its focus on Hizbollah," said FBI spokesman Paul Bresson in Washington.

"Those investigations relate particularly to the potential presence of Hizbollah members on U.S. soil."

There is no specific or credible intelligence pointing to an imminent U.S. attack by Hizbollah, which the United States considers a terrorist group, Bresson added.

But Iran's Hizbollah -- which claims links to the Lebanese group -- said on Tuesday it stood ready to attack U.S. and Israeli interests worldwide.

FBI Director Robert Mueller told reporters in Toronto that agents were keeping a close eye on Hizbollah, especially "when the international situation heats up."

AMERICAN MUSLIMS WORRY

Muslim American groups worry that fear of Hizbollah violence in the United States could again cast an unwelcome spotlight on their community, which has often felt a target of surveillance or discrimination since the September 11 attacks.

Ibrahim Hooper, a spokesman for the Council on American-Islamic Relations in Washington, said his advocacy group fielded almost daily complaints from Muslims who felt singled out or intimidated by government officials.

Muslim American groups say that while they support fighting against terrorism, they are concerned the focus is unfairly on them.

"There are individual concerns that the government does interviews with individuals, with kind of subtle threats that they could be arrested or deported if they don't cooperate. That is really the concern for a lot of these groups right now," said Salam al-Marayati, head of the Los Angeles-based Muslim Public Affairs Council.

"That fact in itself will alienate, frustrate and perhaps even push these young people further to the margins, which creates a very problematic situation for all of us," he said. "In a way, this is becoming a self-fulfilling prophecy."

Marayati, who consults regularly with government officials, said they were listening to his concerns, but should do more to show Americans that their Muslim compatriots are just as determined as they are to fight terrorism.

"Since the relationship is not publicized, people think we're not contributing and Muslims continue to be seen as a problem in our society as opposed to part of the solution," he said.