Gunmen killed eight people in a bar in the northern Mexico city of Monterrey, which has recently seen bloody turf battles between the Gulf Cartel and the Zetas gang.

Nuevo Leon state security spokesman Jorge Domene said a ninth person died apparently when he fell trying to flee the attackers across rooftops. The late Monday attack was on the Matehuala Men's Club.

Domene said Tuesday that some of the victims were bar employees and the attackers fled the scene. Authorities are investigating motives for the attack, but say a recent upsurge in violence is a result of fighting between the Zetas and the Gulf cartels.

In the city of Reynosa, across the border from McAllen, Texas, the Mexican army reported clashes that left four gunmen dead.

The army said a patrol was attacked by armed men in the center of Reynosa and the fighting left four dead. Presumed allies of the gunmen set up roadblocks throughout the city in order to keep army units from moving freely.

The military did not release the identities of any of the slain men.