The nation's top civil liberties group is opening its own front in the battle over Arizona's controversial immigration law, warning travelers that visiting the state could lead to racial profiling.

Critics have said the law, which requires local law enforcement to check the immigration status of people stopped for other reasons, opens the door to warrantless arrests simply for looking like an illegal immigrant, but proponents note that the law specifically forbids racial profiling.

And Gov. Jan Brewer, who signed the law in April, fought back Wednesday against the ACLU's new alert. Her office issued a statement saying that the ACLU's actions proved how "hopelessly out of touch they are with the vast majority of Arizonans, as well as most Americans."

"The legislation includes very specific language that makes it abundantly clear that racial profiling is and will continue to be illegal in Arizona," Brewer spokesman Paul Senseman said. "Instead of spreading fear, hate, and disinformation about the legislation, it would be helpful for the ACLU to instead join Governor Brewer's demand that the federal government stop discussing and begin implementing an honest plan to secure our nation's border."

American Civil Liberties Union affiliates in Arizona, New Mexico and 26 other states put out the warnings in advance of the Fourth of July weekend. The Arizona chapter has received reports that law enforcement officers are already targeting some people even though the law doesn't take effect until July 29, its executive director said.

Sgt. Kevin Wood, a spokesman for the Arizona Department of Public Safety, said Wednesday that its officers were not racially profiling people they come in contact with.

The alerts are designed to teach people about their rights if police stop and question them.

The Arizona law requires police, while enforcing other laws, to question a person's immigration status if officers have a reasonable suspicion that the person is in the country illegally. It also makes it a state crime for legal immigrants to not carry their immigration documents and bans day laborers and people who seek their services from blocking traffic on streets.

Attorneys defending the law against constitutional challenges filed by the ACLU and others argue that the Legislature amended it to strengthen restrictions against using race as the basis for questioning by police. Five lawsuits are pending in federal court, and the U.S. Justice Department is believed to be preparing a legal challenge.

Despite the legislative action, the ACLU still believes that officers will inappropriately target minorities.

"We have a long history of racial profiling in this state, and this is basically going to really exacerbate that problem," said Alessandra Soler Meetze, executive director of the ACLU of Arizona.

The ACLU's warnings were accompanied by a "bust card" that citizens or non-citizens can print out or download to their mobile phone instructing them about their rights during encounters with police.

"There is a tremendous amount of misinformation out there about the law," Meetze said. "It's a very complicated piece of legislation that gives police unprecedented powers to stop and question people about their identity and their citizenship. I think it is important for people to have this information easily accessible."

Arizona's police training board is developing a video training program expected to be revealed Thursday for the state's 15,000 law officers. An outline of the training program said it will teach officers that race and ethnicity cannot be used as targets when enforcing the new illegal immigration law.

Besides ACLU affiliates in Arizona and New Mexico, chapters in Alaska, Arkansas, California, Colorado, Florida, Georgia, Idaho, Kansas, Missouri, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Montana, Nevada, Ohio, Oregon, Tennessee, Texas, Utah, Virginia, West Virginia and Wyoming issued the alerts.