GUADALAJARA, Mexico (AP) _ Prisoners angered by the transfer of their friends to other jails attacked other prisoners Tuesday. Twelve inmates were injured in the melee.

More than 200 prisoners were involved in the brawl in Guadalajara, 290 miles northwest of Mexico City, Jalisco state prison director Ignacio Salazar Mariscal said. Four hundred riot police put down the fighting.

Salazar Mariscal said the fight was started by the ``Black Car'' gang, which was angry over the transfer of 47 of its members to other prisons. He said the gang sold drugs inside the prison and extorted money from other prisoners.