Three of 11 missing Egyptian students are in custody after they entered the United States but failed to appear at their university.

They were part of a larger group of 17 students who arrived in New York on July 29. But only six showed up at Montana State University, in Bozeman, Mont., and the school's officials contacted authorities.

FBI and U.S. Immigration and Customs Enforcement agents arrested Eslam Ibrahim Mohamed El-Dessouki, 21, on Wednesday in Minneapolis.

On the same day, two others gave themselves up in New Jersey after hearing they were wanted by police: Mohamed Ragab Mohamed Abd Alla and Ebrahim Mabrouk Moustafa Abdou, both 22.

"There has been quite a lot of concern, because when students go missing everyone remembers the 9/11 hijacker (Hani Hanjour) who flew the plane into the Pentagon -- he too was here on a student visa," CTV's Joy Malbon told Newsnet from Washington, D.C.

She added that immigration polices have become far more strict since the events of Sept. 11, 2001. Colleges and universities must contact FBI and immigration officials when anyone on a student visa fails to report.

Cathy Conover of Montana State University says background checks for students who are coming to the institution are handled through the federal authorities.

"What we do is we provide a certification of the program itself that they're coming to, that it is a legitimate program," she told CTV's Canada AM.

Former FBI Special Agent George Bauries said the high number of disappearances is unusual.

"If you had one or two of the group that decided they were going off to see Disneyland or Las Vegas, that's understandable," said Bauries. "But for 11 individuals to basically fall off of the radar in the United States, that is a concern."

Cal Temple, of the Terrorism Research Center in Virginia, said the fact the missing students are Egyptian has added an extra incentive to the chase.

"Given the relationship between the al Qaeda network and Egyptians -- al Qaeda's number two guy (Ayman al-Zawahiri) is an Egyptian -- that probably added a little bit of additional urgency to find these guys," said Temple.

While there are approximately 1,300 students who have violated their student visas, "alarm bells started ringing because 11 people, all at once, disappeared," said Malbon.

But Special Agent Richard Kolko told the Associated Press that El-Dessouki's arrest was made "without incident," and that none of the missing students pose any terrorism threat.

One of the group said the missing students probably have been unable to find their way to the university.

"I'm sure that they are lost somewhere in New York. It's a big city and I'm so worried about them," said Mohamed Elsamy.

According to Malbon, the FBI has already revoked their student visas and they will be removed from the United States when found.

With a report by CTV's Joy Malbon and files from The Associated Press