Mexico's top military officer says the army is uncomfortable with the law-enforcement role it was given a decade ago when the government launched an offensive against drug cartels.
The defence secretary, General Salvador Cienfuegos, said the army's presence was supposed to be temporary while new police forces were built, but that hasn't happened.
Many local police in Mexico are corrupt, poorly trained or unreliable.
"We would love the police forces to do their job ... but they don't," Cienfuegos said.
"Ten years ago it was decided that the police should be rebuilt, and we still haven't seen that reconstruction," he said.
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"To sum it up, there are a large number of deaths that shouldn't be happening, there is a lack of commitment on the part of a lot of sectors. This isn't something that can be solved with bullets; it takes other measures and there hasn't been decisive action on budgets to make that happen."
The army has both been the target of attacks by criminals but also has been accused of killing unarmed suspected cartel gunmen.
Cienfuegos said at a year-end meeting that the army needs clearer rules to govern its work in supporting civilian law enforcement, like rules of engagement and the appropriate use of force.
Congress has been considering legislation, but has not yet passed it.
