Mexico City — A Mexican border governor said Monday the death toll from a weekend battle between drug cartel members and security forces has risen to 22. Coahuila Governor Miguel Riquelme said two additional gunmen died overnight. He did not say whether they had died of injuries from Saturday's gunbattle or in subsequent operations.

Police and soldiers have been sweeping the area around Villa Union for those involved. Riquelme told Radio Formula Monday that all hostages have been rescued.

Riquelme said 16 gunmen and four police officers were killed. He said two civilians also were slain by gunmen after being abducted.

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The governor said six more officers were wounded as were four young people who had been taken by the attackers.

Francisco Contreras, an official in the state security agency, said later that the two slain civilians were a firefighter and an engineer who worked for the municipality.

A damaged pick up truck marked with the initials C.D.N., which in Spanish stand for Cartel of the Northeast, sits on a street after a gun battle between Mexican security forces and suspected cartel gunmen, in Villa Union, Mexico, December 1, 2019. Gerardo Sanchez/AP

The reason for the military-style attack remained unclear. Cartels have been contending for control of smuggling routes in northern Mexico, but there was no immediate evidence that a rival cartel had been targeted in Villa Union.

The governor said the armed group — at least some in military style garb — stormed the town of 3,000 residents in a convoy of trucks, attacking local government offices and prompting state and federal forces to intervene. Bullet-riddled trucks left abandoned in the streets were marked C.D.N., the Spanish initials of the Cartel of the Northeast gang.

Several of the gunmen stole vehicles as they fled and kidnapped locals to help guide them on dirt tracks out of town, the governor said. At least one of the stolen vehicles was a hearse headed for a funeral, according to the newspaper Zocalo of Saltillo.

The town is about 35 miles south-southwest of Eagle Pass, Texas, and 12 miles from the town of Allende - site of a 2011 massacre involving the Zetas cartel in which officials say 70 died.

Rapid gunfire could be heard in videos posted to social media along with frantic people telling friends to stay indoors. Images of the aftermath of the shootout showed burned out vehicles, while the facade of Villa Union's city hall was riddled with bullets.

The governor said security forces would remain in the town for several days to restore a sense of calm.

Burned out vehicles are seen next to the City Hall of Villa Union, Mexico, December 1, 2019, after it was attacked by gunmen. Gerardo Sanchez/AP

Falko Ernst, senior Mexico analyst for the non-profit Crisis Group, which seeks to promote peace, said there are few incentives for armed groups in the country to refrain from violence.

"Solving this issue — which underpins impunity —- would have to be the centerpiece of an integrated security strategy. But such a thing is yet to be presented by (President) López Obrador and his team," said Ernst.

"The price of that absence is not least the flaring up of regional conflict scenarios."

Mexico's homicide rate has increased to historically high levels, inching up by 2% in the first 10 months of the presidency of Andrés Manuel López Obrador. Federal officials said recently that there have been 29,414 homicides so far in 2019, compared to 28,869 in the same period of 2018.

The November slaughter by Mexican drug cartel gunmen of three women who held U.S. citizenship and six of their children focused world attention on the rising violence.

Saturday's attack also showed cartels again resorting to quasi-military operations in a brazen challenge to state authority.

In October, a massive operation by the Sinaloa cartel prompted the federal government to release the captured son of a drug lord and pull back the army, which found itself outmaneuvered on the streets of Culiacan.

U.S. President Donald Trump said in a radio interview last week that he plans to designate Mexican drug cartels as terrorist organizations, though he declined to say what actions might follow that designation.

Mexican officials have opposed such a designation, worried it could lead to unilateral U.S. interventions in its territory.

Coahuila state itself has been far from the worst-hit part of Mexico amid violence in recent years. The government census bureau's survey of public perceptions of security found that Coahuila ranked well this year, with only three other states having a higher public perception of safety.