Gunmen stormed a party packed with teenage revelers in Ciudad Juarez early Sunday, killing at least 14 people in the latest spasm of violence to slam the border city, authorities said.

Officials in the northern state of Chihuahua said high school students and others were at a private home celebrating a school soccer victory when armed men rolled up in seven vehicles and opened fire.

At least eight of the dead were younger than 20, officials said. The youngest confirmed victim was 13. At least 14 people were reported wounded.

The motive was not immediately clear. But gatherings in Ciudad Juarez and other Mexican cities have been attacked before as warring gangs pursue targets amid a nationwide drug war.

El Diario, a daily newspaper in Ciudad Juarez, reported on its website that one of the slain teens was a witness in a multiple homicide.

Juarez Mayor Jose Reyes Ferriz announced a reward of 1 million pesos, or about $76,000, for information leading to the capture of the killers, the newspaper said.

Officials said the dead were scattered across three adjacent homes. Investigators recovered at least 82 bullet casings.

Ciudad Juarez has been the most violent corner in Mexico during the last two years, with more than 3,700 people slain as two drug gangs have waged a ferocious battle for control of the important cross-border smuggling passage into nearby El Paso.

The killings have shown no signs of letting up in the new year.

More than 175 people have been slain in the city already in 2010, according to unofficial tallies by Mexican media outlets.

The stubbornness and severity of the violence in Ciudad Juarez have flummoxed the government of Mexican President Felipe Calderon, which declared a war on drug cartels in late 2006.

Early last year, the government created a force of nearly 10,000 military troops and federal police to patrol the city's streets in an attempt to bring the killing under control while a new local police force was being built. But after a brief dip in slayings, the murder rate soared during the second half of 2009, and the death toll of more than 2,000 topped that of a year earlier.

Last month, the Calderon administration took a new tack. Amid widespread complaints that soldiers were trampling people's rights, the government decided to reduce the army's profile by pulling troops off the streets and sent in 3,000 more federal police officers to carry out patrolling and investigative duties.

Elsewhere in Mexico on Sunday, gunmen attacked a police station with assault rifles and fragmentation grenades in Lazaro Cardenas, killing an officer and two civilians, Mexican media reported.

ken.ellingwood@latimes.com

*Cecilia Sanchez in The Times' Mexico City Bureau contributed to this report.