Washington ? The number of people seeking U.S. citizenship has soared since the Sept. 11 attacks, but the government placing a greater effort on weeding out potential terrorists is taking longer to approve applicants.

The new numbers, released by the Immigration and Naturalization Service, reflect a changed America. In the days after the attacks, the government slowed the screening process because of fears of further terrorism, officials said.

Boston-area residents raise their hands as they take the oath of American citizenship during a ceremony at the John F. Kennedy Library in Boston in this April 23, 2002, file photo. The number of people applying for U.S. citizenship has soared since the Sept. 11 attacks but fewer applicants are being approved.

Also, larger numbers of immigrants are seeking the prize of citizenship both to show their patriotism and avoid being caught in the federal dragnet for terrorists that has detained thousands on immigration technicalities since Sept. 11, according to those who work with them.

“People are eager to apply for naturalization because of the problems they run into, or they have a friend who had a problem with INS,” said Ismat Bayumi, 37, of Dallas, who works with people seeking citizenship through the Catholic Charities.

Bayumi, an asylum seeker from Sudan, became a citizen May 23. He applied in November, as soon as he had completed the required five years of living legally inside the United States.

Lisa Gonzales, who admits coming to Houston illegally 12 years ago, applied for citizenship on Sept. 13.

“On Sept. 11, I felt as American as anyone ever has,” Gonzales said. “This is my war, too.”

INS officials said there were 519,523 new applications for citizenship between Oct. 1, 2001, and May 31, 2002 65 percent more than the 314,971 applications received over the same period beginning in 2000.

During May alone, the Immigration and Naturalization Service received 48,378 applications 121 percent more than in the previous May, 21,870.

But even with the increase, the number of people granted citizenship between October 2001 and May 2002 dropped by 10 percent from the comparable period a year earlier, the officials said.

Justice Department officials cite both the increase in applications and a post-Sept. 11 directive urging greater caution in the approval process.