Days after Arizona passed a law that will allow authorities to ask for the papers of any person they suspect of being in the country illegally, Mexico issued a rare travel warning to its citizens.

The warning states: “As long as no clear criteria are defined for when, where and who the authorities will inspect, it must be assumed that every Mexican citizen may be harassed and questioned without further cause at any time.”

The concern of many critics of the Arizona law, and of many Mexicans, is that a person could be discriminated against based solely on his or her appearance. In a White House press conference last week after a meeting with Mexican President Felipe Calderon, President Obama said: “I think the Arizona law has the potential of being applied in a discriminatory fashion.”

Some are pointing back at Mexico, claiming its own immigration laws and practices should be examined for similar reasons.

Some Mexican immigrants – legal and illegal – in the past have claimed to have been harassed by police and others, asked for their documents, treated badly and, even, extorted or raped.

In April, Amnesty International released a report on the abuse of migrants in Mexico, most whom are traveling on to the United States.

“Persistent failure by the authorities to tackle abuses carried out against irregular migrants has made their journey through Mexico one of the most dangerous in the world,” Rupert Knox, Mexico Researcher at Amnesty International, said in a press release.

Amnesty reported that 60 percent of migrant women and girls face sexual violence and that many get contraception injections ahead of the journey to prevent the possibility of becoming pregnant as a result of rape.

“There’s a human rights problem,” said Dr. Jorge Durand, a professor of the study of social movement and author of more than a dozen books on Mexican migration. “Sometimes it is the army, sometimes it is the police; there are many different agents that take advantage of these situations. There is a lot of corruption. And many times the police treat migrants in a really bad manner.”

Many Central Americans, most from Guatemala, are knocking at Mexico’s door — or finding ways to illegally bypass the main entry — hoping to find better paying jobs and a more agreeable lifestyle.

The majority of these immigrants are using Mexico as a pit stop on the way to the United States, experts say.

“There are more and more immigrants in transit,” Durand said. “There are a lot of migrants, everyone can see it. This is not a Mexican issue. This is an American issue.”

Agents at the Instituto National de Migracion (INM), Mexico’s federal bureau of immigration, say that only officers of their agency — and the federal police — are authorized to ask for someone’s documents.

But when asked about extortion and mistreatment of immigrants by others, immigration agent Beatrice Amparo Perez Alatorre said, “I think it happens.”

Both Perez and Durand said that the issues with illegal immigration in Mexico stem from the fact that Mexico is a transit country to the U.S.

“There are many people from Africa, Asia and Europe; [Mexico] is too close to the United States,” Durand said. “This is a long tradition. For more than a century, people who want to go to the U.S. without papers can go through Canada or Mexico. To stop these people — it’s practically impossible.”

According to Durand, the corruption in dealing with immigrants in Mexico stems from the demand coming from the United States.

While the United States is a nation of immigrants, Mexico is not. Some 11.1 percent of the U.S. population was born in a foreign country, according to the 2000 census. Mexico’s 2000 census shows that only 0.5 percent of its people carry this same label. There were 492,617 immigrants in Mexico in 2000, the census shows. The majority, nearly 70 percent, were from the United States; many retirees move to resort areas of the country. The next largest number, about 5 percent, were from Guatemala.

According to the Instituto National de Migracion, some 1.4 million people crossed into Mexico through the southern border in 2004, with 204,000 being stopped due to lack of appropriate documents.

And while there are varying estimates on the number of illegal immigrants in Mexico at any one time, INM agents say the majority are Americans. Many come to Mexico not knowing how long they’ll stay and don’t get the appropriate documents, they say, and end up in the country illegally.

But rather than deporting people who don’t have authorization to be in the country, there is a process for “regularizing” these immigrants.

Illegal immigrants are “never” arrested and sent to jail unless they have committed a crime, Perez said. “We don’t take him and send him to his own country.”

In 2008, Mexico changed its immigration law. Mexico, as does the United States, looks for immigrants who it believes have something to contribute to the progress of the country. And, it seems, they are trying to make this process easy.

“It’s really easy; you can be legal here until you become a citizen,” Perez said.

Once a foreigner has been living in Mexico for five years, he can become a citizen — as long as he has been living in the country legally from the beginning.

Barbara Rudd, 62, has been living in Mexico for more than five years. She and her husband retired to the Lake Chapala region and bought a house in the town of Jocotopec. And while, she says, she doesn’t want to renounce her American citizenship, she does want to stay in Mexico for her remaining days.

On this particular day, she was upgrading her status to “immigrant” after the five-year waiting period.

“I come and go and do what I want,” Rudd said. “It’s so easy to own property … Compared to the U.S., it’s a breeze.”

If someone is found to be living in the country without the appropriate documents, they are required to pay a fine and can go through the process of regularization to get back on track to citizenship.

“To be undocumented in Mexico is not a criminal offense,” Durand said.

According to the “General Law on Population,” Mexico’s immigration law, illegal entry into Mexico, violating terms of a visa, or trying to get back into the country after being deported could result in a fine equivalent to 20 to 100 days of minimum wage in Mexico.

The one violation that may carry a prison sentence: Persons who aid in the transport of illegal immigrants into Mexico risk 12 years in jail and a fine of 10,000 days of minimum wage pay.

But, generally, those in the country illegally are fined, told to make their status legal, and sent on their way.

“[Americans] think if we have strict laws they will have less problems with Central American people,” Perez said. “But I think they’ll always find a way to get to the U.S.”