Gunmen drove up to a house where a high school party was in full swing and opened fire killing 13 people and wounding 17 others, the city public safety agency said Sunday in Mexico's murder capital, Ciudad Juarez.

Most of the victims were "youngsters," said the Chihuahua state attorney general's office.

Witnesses said the gunmen drove up to the house in several cars, first shooting at people gathered outside the dwelling, then pursuing some of the youngsters who jumped over a fence to get away.

"A young man was celebrating his birthday with his schoolmates... and when the host of the party came out to drop off his girlfriend" the shooting broke out, a neighbor told AFP.

Local press reports said the party host's father was among the dead.

Other sources said the young people were members of a local soccer team celebrating a championship victory, the Reforma daily said on its website.

The shooting took place in Ciudad Juarez, the city on the border with the US state of Texas that holds Mexico's record in bloodshed, with more than 2,500 people killed last year in drug-related gangland crimes.

It was the third mass shooting of youngsters in Mexico since September when, within two weeks, 28 youths were killed in two separate shootings at drug rehabilitation centers.