Updated

A gunbattle between soldiers and suspected cartel gunmen left two suspects dead Friday in the northern Mexico border city of Matamoros, authorities said.

Mexico's Defense Department said an army patrol came under fire and two gunmen were killed in the ensuing shootout in Matamoros, across the border from Brownsville, Texas.

Soldiers found four rifles, two pistols and about 1,000 rounds of ammunition at the scene and a bulletproofed vehicle.

A U.S. newspaper reported that Zetas drug cartel leader Heriberto "El Lazca" Lazcano was apparently killed in the gunbattle. But the Defense Department statement said that "the physical characteristics of the dead men allow the conclusion to be drawn that Heriberto Lazcano, leader of the Zetas criminal organization, was not among them."

The Matamoros area has seen frequent battles between the Zetas and their rivals in the Gulf cartel. The gangs frequently kidnap migrants who move through the area, and hold them for ransom.

Lazcano is considered the top leader of the Zetas, considered Mexico's most bloodthirsty major cartel. The United States is offering $5 million and Mexico another $2.5 million in rewards for information leading to Lazcano's arrest.

Also Friday, the government of the Gulf coast state of Veracruz said five suspects died there following a shootout with state police and soldiers.

The state government said in a statement the confrontation occurred when gunmen opened fire on a joint military-police patrol in an area near the border with Tamaulipas state, where Matamoros is located.

The Defense Department also reported Friday that a military helicopter suffered a low-level crash on a training exercise in the southern state of Oaxaca. The craft dropped about five meters (yards) to the ground, injuring the pilot and co-pilot.