Mexican authorities killed a drug cartel leader and 11 other gang suspects in clashes involving ground forces and a military helicopter that fired at the gunmen, officials said Friday.
Juan Francisco Patron Sanchez, a regional leader of the Beltran Leyva cartel, was among those killed in the gun battle late Thursday in the Pacific coast state of Nayarit, the government said.
The navy said in a statement that the skirmish began when the gunmen used "high-caliber" weapons against federal forces who had been following the suspects in the town of Tepic.
"To reduce the level of aggression and lower the risk of death among civilians and federal forces, (troops) repelled the attack with the support of dissuasive fire from a helicopter," the statement said.
A federal official told AFP it was a marine Black Hawk helicopter. Marines were involved in the initial attack and they were later joined by federal police and army troops, the official said on condition of anonymity.
The use of the helicopter allowed ground forces to "control the aggression, resulting in the death of eight suspected lawbreakers," including Patron, the navy said.
Several rifles and handguns, as well as a grenade launcher, were seized.
Federal forces repelled a "second aggression" near Tepic's airport, leaving four more suspects dead, the statement said.
None of the federal forces were hurt.
The interior ministry said Patron was the cartel's leader in Nayarit and part of the neighboring state of Jalisco.
The region is also home to the powerful Jalisco New Generation drug cartel, which brought down a military helicopter with a rocket-propelled grenade in May 2015, killing seven soldiers and a policewoman.
Days after that clash, the federal police, backed by a Black Hawk helicopter, killed 42 New Generation suspects in Tanhuato, a town at the border of the states of Michoacan and Jalisco.
President Enrique Pena Nieto fired the federal police chief last year following allegations that at least 22 suspects were summarily executed in Tanhuato.
Nayarit also shares a border with the northwestern state of Sinaloa, where at least 21 people have been killed since last weekend, including a marine.
The powerful Sinaloa drug cartel used to be allies of the Beltran Leyva crime family, but the groups are now enemies.
The Beltran Leyvas have been weakened in recent years following the capture of kingpin Alfredo Beltran Leyva in 2008, the death of his brother, Arturo, in a shootout with troops in 2009, and the arrest of another sibling, Hector, in 2014.