By David Crowder
EL PASO, Texas, Feb 21 (Reuters) - A woman pushing her child in a stroller in downtown El Paso, Texas, was struck by an assault rifle bullet fired from across the border in Ciudad Juarez, Mexico, on Tuesday, mayor John Cook said.
After Juarez police responded to a carjacking about half a mile from the border, a gunfight broke out between police and the carjackers, Cook said. A bullet -- a type used in assault weapons such as M16s -- penetrated and exited the woman's calf, he said.
The unidentified woman, 48, who was shopping, was treated at a hospital and released with minor injuries, and her child -- whose age Cook did not know -- was not hurt, he said. The mother, a Mexican citizen, is a legal U.S. resident living in El Paso, Cook said.
"I don't think there's any reason for El Pasoans to panic or for anyone else to panic," Cook said. "El Paso still remains a very safe large city."
About 50,000 people have been killed in raging drug violence in Mexico since President Felipe Calderon launched an army-backed offensive against the powerful cartels shortly after taking office five years ago.
More than 10,000 of those deaths have occurred in Ciudad Juarez, Mexico's murder capital across the shallow concrete channel of the Rio Grande from El Paso.
The incident on Tuesday marked the first time that a person in El Paso has been struck by a bullet fired from neighboring Ciudad Juarez since the city began its slide into an abyss of violence in 2008.
That year, Mexico's powerful Sinaloa cartel took on Juarez cartel rivals over turf, littering the city of low-wage export assembly plants with its daily toll of gunshot victims and mutilated corpses.
But rounds fired in Mexico's drug war next door have previously struck buildings in the Texas border city.
Two years ago, bullets fired in a gunfight between a suspected drug gang and Mexican authorities struck city hall, smashing a window. Rounds have also struck a building at the University of Texas at El Paso campus, although no injuries were reported.
Politicians in the United States have voiced fears of possible spillover violence from Mexico, although El Paso, a sprawling southwest Texas city of 700,000 residents, was named the safest city of its size in the United States for the first time two years ago.
And Cook said that violence in Ciudad Juarez and other Mexican border cities has been declining.
"It's unfortunate that a carjacking like this is going to get national attention when Mexico is actually doing a pretty good job controlling the violence," Cook said.
He said there is no indication that Tuesday's incident was cartel-related.
The ordeal prompted two elementary schools and a middle school near the border to be locked down for half an hour, according to El Paso Independent School District spokeswoman Renee De Santos. (Reporting by David Crowder. Additional reporting by Corrie MacLaggan and Tim Gaynor.)