BBC News with Fiona MacDonald

Gunmen have shot dead at least 13 young people at a party in Ciudad Juarez, Mexico's most violent city. At least 15 others were wounded, among them a nine-year-old child. It's the latest massacre in what is Mexico's most violent city. Here is James Read.

Prosecutors said the attackers arrived at the house party at around midnight on Friday in several cars and opened fire with automatic weapons. Local media showed bodies strewn across the garden, and police found more than 70 bullet casings at the scene. In Ciudad Juarez, such killings have become familiar. The city is a battleground between rival drugs cartels, with about 5,000 murders in the last two years alone.