Six women and a man were shot dead in a bar in the northern Mexican city of Ciudad Juarez late Thursday after gunmen stormed the building, police said.
The evening murders came after a bloody day that also saw eight suspected drug cartel members and one soldier killed in a shootout in the north-central Mexican state of Zacatecas.
The killings in the Juarez bar also left two other women seriously injured, in the city, just across the border from El Paso in the southern US state of Texas.
Ciudad Juarez is among those worst hit by the bloody war between feuding drug cartels that has left over 34,200 people dead since December 2006, when President Felipe Calderon launched a nationwide crackdown that has failed to stem the tide of violence.
In the Zacatecas battle, soldiers were investigating reports of gunmen around the city of Tabasco, the defense ministry said. The suspects opened fire at the soldiers, the government said. Tabasco is 190 kilometers (118 miles) north of Guadalajara.
Earlier this week, authorities recovered the bodies of five men dumped on the side of road in Zacatecas after their execution-style slaying.
The deaths raised to 41 the number of people killed last weekend in drug-related violence, particularly in northern Mexico where drug cartels are at war with each other for turf and smuggling routes into the United States.