(CNN)Thirteen Mexican police officers were killed in an ambush Monday in Michoacan, according to local authorities in the violent western state.
Five police vehicles were traveling through the municipality of Aguililla in the early morning when they were ambushed by more than 30 armed individuals, according to a statement from the Michoacan state prosecutor.
The attackers, in five "presumably armored" vehicles, opened fire with high caliber weapons, said the prosecutor, Adrián López Solís.
Security forces dispatched to the scene found officers slain and injured with bullet wounds, their vehicles shot up and two of them on fire, the statement said.
Images published on social media showed posters left on police vehicles signed "CJNG" -- the initials of the Jalisco New Generation Cartel. Reuters cited a state official as confirming the authenticity of the photos, which also showed warnings to police not to support rival crime gangs in the area.
Mexico is struggling to maintain public security amid worsening violence driven by powerful drug trafficking organizations. The state of Michoacan is a strategic transit point and has long been the site of spectacular bloodshed as criminal groups battle for control.
Mexico's security ministry condemned the attack and offered "human and technological resources" to bring the perpetrators to justice.
The ministry initially tweeted that 14 officers had been killed, but the Michoacan state security ministry later confirmed that the death toll was in fact 13, reported CNN en Español.
The Michoacan state security ministry also reported that three more officers suffered injuries in the attack, while prosecutors said 20 had been injured.
The Jalisco New Generation Cartel, a dominant drug gang in the area, is "one of the most powerful and fastest growing in Mexico and the United States," according to the US Drug Enforcement Agency (DEA).
In 2011, the then relatively new group drew worldwide attention when it stopped traffic to dump 35 bodies on a major highway in the city of Veracruz, leaving behind a written message threatening a rival cartel, Los Zetas.
Initially aligned with the vast Sinaloa Cartel led by the now-jailed kingpin Joaquin "El Chapo" Guzmán, the CJNG went on to expand at a lightening pace, establishing itself in seven states within around six months, according to the global consulting firm Stratfor.
The CJNG -- believed to be led by Rubén Oseguera Cervantes, alias "El Mencho" -- has directly challenged Mexican authorities in the past, famously shooting down a military helicopter in 2015.
It is also known for posting video messages featuring uniformed gunmen toting military-style weaponry and equipment.
The Mexican government has been at war with drug traffickers since 2006 and at the same time, cartels have been fighting each other in a brutal campaign for control of territory.
In 2018 there were more than 33,000 homicides in the country -- the highest number since the country began keeping records -- and 2019 is on course to break that record.