Overwhelmed by a flood of citizenship applications, some immigration offices in Southern California are staying open on weekends to get though a backlog of more than 180,000 people hoping to become U.S. citizens.

The U.S. Citizenship and Immigration Services office in Anaheim is doing naturalization interviews on Saturday and Sunday.

Saturday interviews are also available at the East Los Angeles and San Bernardino offices. The agency's Los Angeles District, which covers seven Southern California counties, receives more naturalization applications than any other in the United States, said Jane Arellano, district director.

For now, the Anaheim, San Bernardino and East Los Angeles offices are the only ones open on weekends.

According to the latest agency figures, the Los Angeles office had 127,533 pending applications in January, a 21% increase over April 2007. Orange County had nearly 22,000. By contrast, Miami and New York City -- the areas with the next largest backlogs in the country -- reported 77,417 and 59,348 cases, respectively, in January.

The cost of keeping the offices open on weekends is covered by application fees, which increased from $400 to $675 last summer.

Nationwide, the agency had a 350% increase in applications in June and July 2007 over the same period the previous year. The surge occurred just before August's fee increase.

Local immigration officials say weekend schedules and longer hours have cut the wait time for applicants.

Still, the wait can fluctuate. Using data from January, Arellano said the wait was about nine months.

Los Angeles immigration attorney Monica Kane said a wait of nine or 12 months "is pretty much on target."

"We represented an applicant who was interviewed in February, and he applied in April 2007. That's about 10 months. We're finding that nine to 12 months is a reasonable estimate," Kane said. "But everyone wishes it could be shorter."

Earlier this month, Citizenship and Immigration Services Director Emilio T. Gonzalez estimated that it would take 13 to 15 months to process all cases nationwide. He said the wait was an improvement over the 16- to 18-month projection the agency made in late 2007.

Pasadena immigration attorney Fred Benson said that as recently as 2006 his clients were waiting only five to seven months. "That was pretty much standard then, but I was also getting appointments in four months. But given how things are today, I don't think waiting a year is a terrible thing," he said.

Some of his clients who filed applications in July are scheduled for interviews this month, he said.

The agency has come under severe criticism for not preparing adequately for the anticipated deluge of citizenship applications before fees increased.

Gonzalez said 1.4 million citizenship applications were filed in 2007; 460,000 in July alone. The yearly total was almost double the number for 2006.

In addition to overtime and weekend schedules, Arellano said the Los Angeles district plans to hire 100 workers by the fall to speed up processing of immigration applications.

The agency announced plans this month to work with the FBI in speeding up background checks, which can slow down an application by years. Officials hope to complete all checks that have been pending for more than three years by next month and those waiting for more than a year by November. According to an agency statement, 98% of all name checks will be completed within 30 days starting in June 2009.

hgreza@latimes.com