Updated

MONTERREY, Mexico (AP) — Mexican soldiers killed at least 30 suspected cartel members in two shootouts near the U.S. border in a region that has become one of biggest battlegrounds in the country's drug war, authorities said Friday.

Twenty-five of the suspects were killed Thursday during a raid on a building in Ciudad Mier in Tamaulipas state. The other five were killed Friday in neighboring Nuevo Leon state, during a shootout on a highway leading to the border, the Mexican Defense Department said in a statement.

All 30 gunmen were believed to belong to the Zetas gang — the group suspected of killing 72 migrants nearly two weeks ago in what could be Mexico's biggest cartel massacre to date.

Violence along Mexico's northeastern border with Texas has reached warlike proportions amid fighting between security forces and two feuding drug gangs — the Zetas and the Gulf cartel, former allies who split this year and started a vicious battle for trafficking routes in the area.

One of two survivors of the massacre last month — an Ecuadorean — said the killers identified themselves as Zetas and gunned down the migrants because they refused to work for the gang.

A military aircraft flying over Ciudad Mier on Thursday spotted several gunmen in front of a building, the Defense Department statement said. When ground troops moved in, gunmen opened fire, starting a gunbattle in which 25 suspected cartel members died and two soldiers were wounded.

Authorities rescued three people believed to be kidnapping victims in the raid, according to the statement. The military said troops seized 25 rifles, four grenades, 4,200 rounds of ammunition and 23 vehicles.

Earlier, a military spokesman said the gunmen were believed to be on a property controlled by the Zetas.

The second shootout erupted Friday morning outside the town of Juarez in Nuevo Leon, on a highway leading to McAllen, Texas.

Soldiers went to the area after receiving an anonymous tip that armed men were circulating in a black SUV, according to a military spokesman. He provided the information on condition of anonymity because he was not authorized to reveal his name. The spokesman said the armed men opened fire, provoking the shootout that killed five gunmen, all of whom were believed to be Zetas.

Drug violence has claimed more than 28,000 lives since President Felipe Calderon intensified a crackdown on cartels after taking office in late 2006.