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SALT LAKE CITY -- Immigrant and civil rights groups filed a lawsuit Tuesday to try to block a Utah immigration law that they say will create a police state and is too much like one of the most controversial parts of Arizona's immigration law, which is also before the courts.

The Utah law, signed by Gov. Gary Herbert in March, requires people to prove their citizenship if they're arrested for a felony or class-A misdemeanor.

Marielena Hincapie, executive director of the National Immigration Law Center, said it violates civil rights and other constitutional protections because it could lead to police requiring everyone they pull over to prove their legal presence in the country.

"This is racial profiling and civil rights violations at its worst," Hincapie said.

The law center and the American Civil Liberties Union filed suit Tuesday in federal court in Salt Lake City. They're seeking an immediate injunction against the law, which is set to take effect May 10.

Utah Attorney General Mark Shurtleff said the measure is "completely defensible" because, unlike Arizona's law, it requires police to check citizenship only when a person is arrested for a felony or class-A misdemeanor. Officers can use discretion for minor offenses, such as a traffic violation.

Arizona's law includes a provision that would require officers who are enforcing other laws to question the immigration status of those they suspect are in the country illegally. That provision and others are on hold pending a trial.

Shurtleff said the Utah Legislature also removed a "reasonable suspicion" provision from House Bill 497 before it passed, which could have led to racial profiling.

"We don't want to violate anyone's civil rights," he said.

Herbert spokeswoman Ally Isom added the immigration law was passed because the federal government has neglected its duty. While crafting the legislation, the state worked very hard to stay within constitutional boundaries.

Isom said the groups would be better served "proposing and advocating realistic immigration reform rather than pursuing litigation against those who are trying to deal with our current problems."

The ACLU and National Immigration Law Center filed the suit on behalf of several other organizations, including the Utah Coalition of La Raza, the Service Employees International Union and the Latin American Chamber of Commerce.

Archie Archuleta of the Utah Coalition of La Raza said the law still is damaging to immigrant communities because police could check anybody's citizenship. That will deter people from talking to police.

"We leave too much in the hands of officers to determine whether I or you or anyone else is undocumented," Archuleta said.

By passing the law, Utah is attempting to trump federal authority to control immigration, said ACLU managing attorney Cecillia Wang. The state is also violating the interstate commerce clause because it won't accept driver's licenses from states that don't require people to prove citizenship.

"As Americans, we enjoy the freedom to go about our business without having to show our papers," Wang said. "HB 497 undermines that freedom."