Ciudad Juarez (Mexico), Feb 1 (Inditop.com/EFE) Thirteen people were killed and 16 wounded when gunmen opened fire at a birthday party in Mexico’s border city of Ciudad Juarez, officials said.

The incident took place at 1.30 a.m. Sunday in a lower middle-class neighbourhood in Juarez.

About 60 people, mostly teenage students, were attending the party when the attack took place.

More than 20 gunmen in seven vehicles arrived at the house, went inside and opened fire, eyewitnesses said.

The wounded were taken to a nearby hospital.

Two adults and 11 teenagers were among the dead. Some of the wounded are in critical condition, hospital officials said.

This is the worst shooting so far this year in the city, which has been plagued by drug-related violence for several years.

Ciudad Juarez, with 191 homicides per 100,000 residents, was the most violent city in the world in 2009.