At least 22 people have been killed in gun battles in Mexico. According to the government, heavily armed men assaulted police units in six coordinated attacks in Michoacan state.
The gunmen reportedly hid in hills above checkpoints and blocked four sections of highway before storming their targets.
The Tierra Caliente region is a gang violence hot spot. In May, the government pledged to keep thousands of troops on the ground to keep the peace in Michoacan, an area plagued by drug cartels.
Vigilante groups sprang up in response to a recent crime wave and the rise of a new powerful cartel known as the Knights Templar.
Michoacan has been home to drug gangs for decades, where they grow marijuana and opium poppies for illegal shipping to the USA.