PIEDRAS, NEGRAS, Coahuila – State police officers placed the local Coahuila Attorney General’s Office on lockdown following the arrests of 10 cartel gunmen who allegedly took part in a recent shootout that led to at least 21 deaths. The move is a precautionary measure in case other gunmen try to rescue their comrades.

On Saturday, approximately 150 gunmen from the Cartel Del Noreste faction of Los Zetas stormed the town of Villa Union in a brazen attack where they shot the city hall building, torched police vehicles and engaged authorities in an hours-long firefight that killed 21 people. Subsequent information released by authorities revealed the gunmen kidnapped four adults and three children as well as carjacking two U.S. men on a hunting trip. Two of the victims were local firefighters who were later found dead while the rest have since been released unharmed. Authorities said that 17 cartel gunmen and four police officers died in the clashes.

On Tuesday, Coahuila authorities announced they arrested 10 suspected gunmen, seized 18 armored SUVs, 21 caliber .223 rifles, six .50 caliber Barret Rifles, and several tactical clothing items. The arrests of the 10 gunmen in addition to the 17 dead suggests at least 120 are still at large.

Following the arrests, authorities took them to the Coahuila Attorney General’s Office in Piedras Negras, where Attorney General Gerardo Marquez Guevara told his agents to prepare for the worst and not back down in case of an attack.

Fearing a possible rescue attempt, Marquez Guevara ordered his staff and officers from a special unit of the Coahuila state police set up a security perimeter with reinforced entrances. The government building is approximately 3.5 miles from the Texas border.

Wednesday morning, Coahuila prosecutors continued their questioning the captured gunmen and are working the ongoing investigations before taking cases to a state judge. The attorney general’s office remains under lockdown.

Editor’s Note: Breitbart Texas traveled to the Mexican States of Tamaulipas, Coahuila, and Nuevo León to recruit citizen journalists willing to risk their lives and expose the cartels silencing their communities. The writers would face certain death at the hands of the various cartels that operate in those areas including the Gulf Cartel and Los Zetas if a pseudonym were not used. Breitbart Texas’ Cartel Chronicles are published in both English and in their original Spanish. This article was written by “J.M. Martinez” from Coahuila.