The border city of Ciudad Juárez, abutting El Paso, Texas, announced the gradual re-deployment of joint police and military patrols to quell cartel violence and enhance local security.

The implementation of joint patrols involving elements of state, federal, and municipal police in conjunction with the Mexican Army was announced by Ciudad Juárez Mayor Héctor Armando Cabada and State Security Director Oscar Aparicio, according to local reporting. The joint operation was initiated this week and includes a plan to map out cartel hotspots.

The joint patrols were initially deployed in late October after police personnel suffered 10 attacks from cartel gunmen in less than one month–leaving two officers dead and several wounded. After the surge, violence began to trend downward until recently. During the months of September and October, homicides were significantly down compared to the summer, but attacks against security personnel spiked at an alarming rate.

The most recent violence is attributed to splits between street gangs aligned with warring cartels as they fight for methamphetamine street sales. The “Mexicles” and “Artistas Asesinos” were previously aligned with the Sinaloa Cartel, yet are now at war with each other after a faction of Mexicles re-aligned with “La Línea” and “Los Aztecas,” the deadly rivals of the Sinaloa gangs. In another area of Ciudad Juárez, an “Old Guard” faction of Los Aztecas is warring with a newer faction of “Los Aztecas.” These splits are contributing to numerous homicides and attacks against official personnel.

On Tuesday, the municipal police arrested three gang members belonging to a faction of the Sinaloa-aligned Los Mexicles after police found nearly 56 pounds of methamphetamine inside their vehicle, according to local reporting.

The all-time homicide record for Ciudad Juárez was set in 2010 with 3,075 officially recorded. The 2018 unofficial count exceeds 1,200, according to local media and statistics compiled from the state attorney general’s office.