Dozens of Pakistani immigrants who came to the United States posing as religious workers were arrested Wednesday, authorities said, as Homeland Security agents tried to close a commonly exploited avenue for illegal immigration.

Immigrants who were supposed to be teaching or conducting religious ceremonies were arrested across the East Coast, where authorities said many worked as gas station attendants, taxi drivers, landscapers and factory workers.

U.S. Immigration and Customs Enforcement officials have been scrutinizing the religious worker visa program, which a 2005 review found was rife with problems. Homeland Security officials found fraud in one of every three religious visas they reviewed.

Churches that sponsored the workers turned out not to exist, workers could not be found and addresses could not be verified, the study said. In one incident, the address on the visa application was found to have been used by a terrorist suspect.

Most of the 33 people arrested Wednesday were from Pakistan. Authorities said there was no indication of a terrorist threat. U.S. Immigration and Customs Enforcement said the aliens paid large fees to get people or organizations to sponsor them for visas.

Arrests were made in Connecticut, Georgia, Massachusetts, Minnesota, New Jersey, New York, Pennsylvania, Virginia and Washington D.C.

In June, Washington state pastor Dong Wan Park was convicted of helping South Korean nationals file fraudulent religious visa applications. None of the applicants was ever employed at the church.

The aliens arrested Wednesday were held on immigration violations and could face criminal charges.

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