Gun battles between Mexican government forces and gunmen on roads between the border cities of Reynosa and Matamoros have killed eight suspected criminals.

The government of the border state of Tamaulipas said late Tuesday a ninth suspect apparently died in n area shootout with a rival gang.

"Rolling gun battles" were reported in the region by the U.S. Consulate in Matamoros, which advised its employees to stay off the streets.

The two cities are dominated by the Gulf drug cartel, which has seen internal divisions and turf battles with the rival Zetas gang.

Gang members had apparently been preparing for a battle by blocking roads around the two cities.

The state government on Monday reported a pair of attacks on marine patrols in the area that killed five suspects.