Troops clashed with gunmen as people headed to work and school in a southern Mexican town on Wednesday, leaving 10 suspects and one soldier dead, prosecutors said.
The soldiers were on patrol in the streets of Tepecoacuilco, a town 200 kilometers (124 miles) south of Mexico city, when they were jumped by gunmen, sparking a shootout, the Guerrero state prosecutor's office said.
Guerrero is known for the Pacific beach resort of Acapulco but it has been among the states worst hit by Mexico's brutal drug war.
The federal government deployed more than 7,000 troops and police in Guerrero last year to try to put a lid on the violence.
Some 60,000 people have died across Mexico since December 2006, when the government unleashed a military offensive against powerful drug cartels.