More than 5,000 Mexicans may have died in the past 15 years while making the often perilous journey to try and sneak into the United States, Mexico's National Human Right Commission said on Thursday.
"The estimate on the number of victims is not certain, and ranges from 3,861 to 5,607," CNDH president Jose Luis Soberanes said, presenting the report based on official figures and completed in collaboration with the American Civil Liberties Union (ACLU).
Some rights groups say up to 10,000 people may have lost their lives during the same period in trying to reach the United States, now home to an estimated 12 million immigrants.
The CNDH called for the deaths of immigrants at the often violence-plagued southern US border to be "recognized as part of an international humanitarian crisis," Soberanes said.
The number of deaths spiked in 1994, when the United States launched Operation Guardian to reinforce controls at the California border and later at the border with Arizona and Texas states, he explained.
Although the deaths are largely accidental, they are linked to what the CNDH chief called the "extreme risks" undertaken by the clandestine travelers to avoid immigration controls: torrents, steep mountains and deserts.
Some 27 people have already drowned to death since January in the Rio Grande river (Rio Bravo) that marks the northeastern Mexican border with Texas, according to local authorities.
Only a small portion of the illegal immigrants are killed by border police -- seven between 1994 and 2007, according to the report.
The strategy of bolstering controls and the "militarization" of the border "has not limited immigration," Soberanes said.
"This policy of contention has failed," he added, because the number of illegal immigrants has increased in parallel with boosted surveillance measures -- growing from 8.4 million to 11.9 million between 2000 and 2008.
Soberanes pointed to another consequence: a price increase for those organizing the increasingly hazardous journey, which has boosted this "market" for "organized crimes" and drug cartels that are now also involved in the potentially lucrative business.
Mexico has asked US authorities to investigate Tuesday's shooting in the border city of Tijuana that left four people wounded and closed the San Ysidro crossing into San Diego, California for several hours.
The CNDH suspects criminal groups were involved.
The US border security budget has jumped from six billion to 10 billion dollars in the past five years. About 20,000 border guards have been deployed and a virtual electronic network of detection has been installed.