Mexican troops on patrol killed 12 gunmen in a clash near the U.S. border in Tamaulipas, according to the government of the northeastern state, which has been rocked by violence linked to organized crime. The slain attackers were alleged members of a drug cartel, government sources told AFP.

The shootout occurred when soldiers were patrolling Miguel Aleman municipality on the border with the United States, the office of Tamaulipas's spokesperson for security said on social media.

It said members of the Secretariat of National Defense (Sedena) "were attacked by armed civilians who were hiding in the bush" at around 2 pm local time.

The clash left a dozen assailants dead and soldiers seized "12 long weapons, cartridges and magazines of various calibers," it added.

State government sources confirmed to AFP that the 12 attackers, alleged members of a drug cartel, were killed in the incident, during which the military also used drones and a helicopter.

Situated on the U.S. border, Tamaulipas is one of the states hardest hit by violence linked to organized crime.

It is the site of constant clashes between gangs fighting over lucrative drug trafficking routes.

Four U.S. citizens, two of whom later died, were kidnapped at gunpoint after crossing the border into Tamaulipas state in a minivan in March last year. Americans Zindell Brown and Shaeed Woodard died in the attack; Eric Williams and Latavia McGee survived. A Mexican woman, Areli Pablo Servando, 33, was also killed, apparently by a stray bullet.

The Gulf drug cartel turned over five men to police soon after the abduction. A letter claiming to be from the Scorpions faction of the Gulf cartel condemned the violence and said the gang had turned over to authorities its own members who were responsible. 

Last month, Mexican marines detained one of the top leaders of the Gulf cartel. Mexico's Navy Department said in a statement that marines had detained a suspect it called "one of the key leaders of one of the most powerful criminal organizations in Tamaulipas," adding he was "one of the main targets of the Drug Enforcement Administration," but did not provide his name.

Mexico has registered more than 420,000 murders and 110,000 disappearances -- most attributed to criminal groups -- since the launch of a controversial military anti-drug offensive in 2006.

The Associated Press contributed to this report.

In:
• Mexico
• Cartel