MEXICO CITY (AFP) - Heavily armed men clashed with federal police in six towns in Mexico's Michoacan state, leaving 22 people dead in the bloodletting, the Interior Ministry announced on Tuesday.
"So far, we have two federal police killed, 20 presumed criminals shot dead and another 15 people under arrest," the ministry's National Security Council said in a statement.
In May, Mexico's government promised to keep thousands of troops in the western state until peace is restored to a region that is tormented by violent drug cartels.
Interior Minister Miguel Angel Osorio Chong held a meeting of the national security team in the state capital Morelia with local officials to discuss a crime wave that led some towns to create vigilante groups.
Officials said some 4,000 army soldiers and marines and 1,000 federal police officers were deployed at that time. Mr Osorio Chong also said the forces would leave once security conditions have improved and the state government can hold its own.
Michoacan was the first state to see troops when former president Felipe Calderon decided to deploy tens of thousands of soldiers across the country to crack down on drug cartels in 2006.
But gang violence surged throughout Mexico, leaving 70,000 people in its wake when Mr Calderon left office in December, and a powerful new cartel, the Knights Templar, emerged in Michoacan.
Mr Osorio Chong has insisted that the strategy ordered by current President Enrique Pena Nieto will be different than his predecessor's, with a single command, close coordination between various authorities, greater use of intelligence assets, and a development program.
Mr Pena Nieto took office in December vowing to switch the focus towards reducing the levels of violence. He has since launched a crime prevention programme but he says troops will stay on the ground until the murder rate goes down.
Fed up with crime, vigilante groups have appeared in recent months and clashed with the Knights Templar cartel, notably in the Tierra Caliente region known as a hot spot of gang violence in the state of 4.3 million people.
Drug gangs have existed for decades in this western state, where they grow marijuana and opium poppies and produce synthetic drugs in makeshift labs before shipping them to the United States.