The military said the arrest of the suspect, whom it did not identify, was made in Saltillo, Coahuila state, as gang members unleashed a hail of gunfire in an apparent failed attempt to cover his escape.
The suspect “is considered the operational chief for the criminal operations of the Zetas criminal group in Coahuila, Nuevo Leon and Tamaulipas states,” the Defense Ministry said in a statement.
It said he was also a top lieutenant of cartel chief Heriberto Lazcano, in which case the arrest would be one of the largest blows ever dealt to the organization.
The arrest followed running street battles involving troops, police and gang members in which a taxi driver was killed and eight other people were wounded, including three police, the Coahuila state prosecutor’s office said.
Authorities said the suspect would be presented to the media on Thursday.
The arrest came the day after the United States accused Iranian operatives of having tried to contact a Mexican drug cartel as part of a plot to kill the Saudi ambassador in Washington.
Officials did not specify which of Mexico’s powerful cartels was allegedly approached, but US media reported that it was the Zetas, a notorious drug cartel made up of former Mexican special forces.
The Zetas have been accused of a string of killings, kidnappings and macabre displays of brutality that have made them one of the most feared gangs in Mexico’s spiraling drug violence.
Set up in the 1990s by ex-elite soldiers turned hired killers, the Zetas are fighting their former allies the Gulf cartel and others.
More than 45,000 people have been killed in drug-related violence since Mexico launched a massive military operation against the cartels in 2006 involving some 50,000 troops.
Earlier on Wednesday, the navy said it had found the body of a man it described as the “chief financial operator of the Gulf Cartel” in Reynosa, Tamaulipas state, without saying who was behind the killing.
Last week Mexican troops detained 32 alleged Zetas members, including 18 municipal police officers, in the eastern state of Veracruz.
The sting came after the bodies of 35 people, most with criminal records, were dumped on a road in Veracruz city in broad daylight. The killings were claimed by a shadowy new vigilante group calling itself the “Zetas Killers.”