Three security forces were wounded and 10 suspected criminals killed in a shootout in Mexico State bordering the capital Mexico City, state officials said on Tuesday.
Violence has plagued the government of President Andres Manuel Lopez Obrador, who has pledged to pacify the country with a less confrontational approach to dealing with crime.
Mexico State's prosecutor's office said on Twitter that during an operation in the small municipality of Texcaltitlan "a heavily armed group attacked" its security forces, three of them sustaining non-life-threatening injuries.
Meanwhile, 10 suspected criminals were killed and seven were arrested, four of them injured.
State security forces seized 20 long weapons, handguns, cartridges, five vehicles, bulletproof vests, military-style uniforms, and communications equipment.
Violence in Mexico spiked after former President Felipe Calderon sent the army into the streets to fight drug traffickers in 2007, unleashing a wave of violence that has not abated.
While Lopez Obrador inherited a nation already reeling from a high murder rate, since taking office average annual homicide totals are on track to be the highest under any Mexican administration since modern records began.
His security policy, which he termed "hugs not bullets," has faced sharp criticism for being soft on crime.
