Piedras Negras, across the Rio Grande from its sister city of Eagle Pass, is bracing for more violence as the Zetas cartel tries to fend off rival cartels and the Mexican military.
"Some of the Zeta leaders are being captured. Their hierarchy is crumbling," said Lt. Moses Pena with the Eagle Pass Police Department.
The Meixcan Nay's latest capture was a Zetas founder known as "El Taliban."
It was a major blow for the cartel already racked by in-fighting.
Lt. Pena said federal and local authorities on the U.S. side remain on high alert as a precaution.
The U.S. Consulate also issued a travel advisory urging Americans there to exercise caution.
On Wednesday, several running gun battles were reported throughout much of Piedras Negras.
At least one woman was killed in her vehicle, caught in the crossfire, according to Benito Ramirez, who serves on the Piedras Negras city council.
Ramirez said a police vehicle was also torched within sight of his office.
"I was on the floor, so we didn't see much," Ramirez said. "This is something we don't want to get used to."