The Mexican army has arrested a second person in connection with last weekend's bloodbath in Ciudad Juárez.

The authorities say the 24-year-old man has admitted involvement in the shooting at a party in which 15 young people were killed.

Twelve others were injured when a gang of armed men stormed the party.

One day later police shot dead a men they believed to be the brain behind the attack in an exchange of gunfire. A 30-year-old man was arrested.

It is not clear what the motive was behind the attack. It is thought that the gang may have been out to kill members of a rival gang.

Photo: Mexican death figures - Flickr/Chimimexx