Mexico City - A most-wanted founder of Mexico's ultra-violent Zetas drug cartel has been killed in a clash with the military that involved grenades and assault rifles, authorities said on Monday.
Galdino Mellado Cruz, a military deserter known by the alias Z-9, was killed in one of two gunfights in the northern border city of Reynosa on Friday that also left five civilians and a soldier dead.
The skirmish came amid a surge in violence in the north-eastern state of Tamaulipas that has left more than 80 people dead since 5 April, including the state police's chief of investigations.
Intelligence work led the troops to a house in Reynosa where Mellado was hiding, said Monte Alejandro Rubido, the national security commissioner.
Grenades were lobbed from the house and shots fired at the soldiers. Several carloads of gunmen arrived at the scene with assault rifles, apparently to help Mellado.
When the clash ended, Mellado was found dead inside the house next to a submachine gun, Rubido said.
'Internal power struggle'
Rubido said Mellado was the number two leader of a criminal group operating near the US border and the founder of another gang. He did not name the gangs.
But Mellado was known as one of the elite Mexican soldiers who deserted from the army and founded the Zetas to work as hired guns for the leader of the Gulf cartel, Osiel Cardenas Guillen.
After Cardenas Guillen's capture in 2003, the Zetas began to operate more independently until they finally broke with the Gulf cartel in 2010, unleashing a war for control of its drug trafficking routes in eastern and north-eastern Mexico.
The two groups have been locked in a violent struggle for Tamaulipas, whose capital Reynosa sits across the border from McAllen, Texas.
The latest bout of violence is partly blamed on an internal power struggle within the Gulf cartel.
The federal government is expected to announce a new security strategy for Tamaulipas on Tuesday.