By Noe Torres
MEXICO CITY, June 19 (Reuters) - Rights groups on Wednesday raised concerns over Mexico's use of security forces to curb illegal migration after prosecutors said they were investigating the death of a young woman in an alleged shooting of Salvadoran migrants by police last week.
The incident, in which the 19-year-old woman was killed and two men were wounded, occurred on Friday in the eastern state of Veracruz amid a push by Mexico to stem the flow of U.S.-bound migrants entering Mexico from Central American.
Mexico is under pressure to halt the flow to avoid punitive tariffs by U.S. President Donald Trump.
"This would be the first person killed by the plan to contain migration," activist Ruben Figueroa of migrant rights' group Movimiento Migrante Mesoamericano wrote on Twitter.
"The hunting of migrants on the southern border is intensifying," he said.
On Saturday, Mexican migration officials detained nearly 800 migrants in trucks moving through Veracruz.
Veracruz Attorney General Jorge Winckler said survivors of the shooting - part of a group of 17 Salvadorans traveling in a pickup - said three men who were "apparently police" began pursuing them in what appeared to be a patrol car after they passed an immigration checkpoint.
The men fired several shots, then fled, Winckler said. It was unclear why they opened fire, and Veracruz authorities are investigating. Criminals sometimes pose as police in Mexico, but there was no immediate indication that was the case in Veracruz.
Mexico has vowed to reinforce its southern border with 6,000 members of a new National Guard as part of its agreement with the United States to contain migration.
President Andres Manuel Lopez Obrador's decision to deploy security forces has been questioned by activists and human rights organizations. They argue that migrants could become even more vulnerable after many of left their homes to escape violence and criminal gangs in Central America.
Mexican Foreign Minister Marcelo Ebrard, who defended the National Guard deployment, said measures like Saturday's detentions could save the lives of hundreds of people forced to travel in dangerous conditions by human smugglers.
"Mexico is making an effort to regulate (migration). This doesn't have to be a violation of human rights: our government would not be prepared do that," Ebrard said in New York after meeting with the U.N. Secretary General Antonio Guterres.
"The fact the National Guard is taking part doesn't mean it's going to violate anyone's rights," he added. (Reporting by Noe Torres Editing by Daniel Flynn and Tom Brown)
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