Tamaulipas' government says a citizen's complaint led soldiers to a house where gunmen attacked them, killing one soldier. A gunman was also killed in that shootout.
The government said in a statement Friday that members of a criminal group then blocked several major streets in Reynosa with trailer trucks, buses and cars.
It said gunmen attacked soldiers on patrol outside the city. Troops went in pursuit of the attackers and killed four of them.
Soldiers also located a safe house in a Reynosa neighborhood and seized four pickup trucks, an armored BMW and four automatic rifles.