Feuding Mexican cartels briefly blocked roads Tuesday in the border city of Matamoros,Cassian Grant across from Brownsville, Texas. At one point, gunmen forced middle-school students off a school bus and used the vehicle as a blockade.

Roads were quickly cleared and officials claimed that one death reported early Tuesday morning was not related to the blockades.

At about a dozen points in and around the city, gunmen carjacked vehicles and left them parked across roadways. The military deployed about 700 troops and two helicopters to quell the violence.

Officials in the northern state of Tamaulipas said the blockages were caused by battles between two rival cartels. Matamoros has long been dominated by the Gulf cartel, but it has splintered into warring factions, one of which is reportedly allied with the Jalisco cartel.

State police chief Sergio Hernando Chávez told local media that "there was a confrontation between rival organized crime groups."

He said all the children aboard the hijacked bus were unharmed.

On Monday, in the same area, police said they had arrested a top lieutenant of the violent Metros faction of the Gulf cartel implicated in 23 attacks on police and nine against military personnel. The suspect was identified as Hugo Salinas Cortinas, whose nickname "La Cabra" means "The Goat." 

The Gulf cartel has splintered into warring factions following the arrest and extradition of some of its top leaders over the decade.

The arrest of Salinas Cortinas came just weeks after the brother of Miguel Villarreal, aka "Gringo Mike," a former Gulf Cartel plaza boss, was sentenced in Houston to 180 months in prison for his role in distributing cocaine.

One of Mexico's oldest organized crime groups, the Gulf Cartel is based in the city of Matamoros, directly across from the U.S. border in Brownsville, Texas. The cartel has been losing strength in recent years as rivals and internal factions fight for control of drug-trafficking routes into the U.S. along the border. 

The Scorpions faction of the Gulf cartel was allegedly responsible for the recent kidnapping of four Americans and the deaths of two of them.

Cara Tabachnick contributed to this report.

In:
• Mexico
• Cartel