Gang battle leaves 49 dead in Mexico prison

A battle between rival groups at a prison near Monterrey in northern Mexico has left 49 inmates dead.

Nuevo Leon state Governor Jaime Rodriguez said 12 other people were injured in Topo Chico jail after prisoners fought with "sharp weapons, bats and sticks".

Rodriguez said the fight had started around midnight and lasted 30 to 40 minutes, during which time the two groups of inmates set fire to a storage area.

He said one faction was led by a member of the notorious Zetas drug cartel, Juan Pedro Zaldivar Farias, also known as Z-27. 

Rodriguez said the other group was led by Jorge Ivan Hernandez Cantu, whom Mexican media identified as a member of the rival Gulf cartel.

A fire was also started in a storage room. Officials say the situation is under control and no inmates escaped.

Crowds of relatives outside the jail blocked roads, demanding information. Some threw sticks and rocks and tried to pull the prison gate open as riot police blocked their way.

The incident comes just days before Pope Francis is due to visit a prison in the northern city of Ciudad Juarez, an area notorious for violence between drugs cartels.