Suspected drug hitmen burst into a party and killed 13 people, most of them teenagers, on Sunday in Ciudad Juarez, the latest massacre in one of the world's deadliest cities, Mexican media said, Reuters reported.
Gunmen jumped out of sport utility vehicles and fired at people in a house in the city across border from El Paso, Texas, in the early hours of Sunday, newspapers El Diario and Reforma said.
Police and officials in Ciudad Juarez confirmed the shooting but declined to give more details.
Ciudad Juarez is the bloodiest city in Mexico's drug war as rival cartels fight over markets and control of smuggling routes into the United States.
Gunmen have stormed at least seven drug rehabilitation clinics in the manufacturing city over the past two years in attacks that target rival dealers. Two strikes in September killed 28 people.
Mexico is the key transit route for U.S.-bound cocaine from South America and a top producer of marijuana and heroin.
A military crackdown on rival cartels in Mexico has fueled a surge in drug violence that has killed more than 17,000 people over the past three years.