A shootout between soldiers and purported drug cartel gunmen killed 25 suspects in northern Tamaulipas state, near Mexico's border with Texas, the military said.
Troops were patrolling on Thursday in the town of General Trevino around noon when they came under fire from a ranch allegedly controlled by the Zetas drug gang, according to a military spokesman who was not authorized to be quoted by name.
They returned fire and invaded the ranch, known as "The Stump." At least 25 suspected cartel operatives died, but no soldiers were killed or wounded seriously, the spokesman said.
Authorities rescued three people believed to be kidnap victims, he added, and seized 20 vehicles and an unspecified quantity of weapons and ammunition.
Drug violence has claimed more than 28,000 lives since President Felipe Calderon intensified a crackdown on cartels after taking office in late 2006.
The Zetas began as a gang of drug assassins but have since evolved into a powerful cartel. A fight between the Zetas and their former allies, the Gulf cartel, has increased the rate of killings in Tamaulipas and elsewhere, according to government figures.
The Zetas are suspected of being responsible for the kidnapping and killing of 72 Central and South American migrants in Tamaulipas last week, in what could be Mexico's biggest drug-related massacre.