Story highlights Riot breaks out among inmates at a prison in Tamaulipas, authorities say

Prisoners use homemade knives; 7 are killed and 2 more are injured

9 inmates were taken away and could face punishment

Seven inmates were killed during a prison riot Saturday in Mexico's Gulf Coast state of Tamaulipas, authorities said.

Two other prisoners were injured in the melee in Altamira, a prison located about 300 miles (480 kilometers) south of the U.S. border, Tamaulipas state officials said in a statement. The situation reportedly was under control within an hour.

Nine inmates were taken away and could be subject to punishment for their alleged roles.

The riot began at 6 p.m. (7 p.m. ET) when inmates wielding homemade knives went at each other during a fight.

The ages of the inmates involved -- who were serving time for both federal and state crimes -- ranged from 20 to 59.

Saturday's incident took place in the same prison where 31 inmates died and another 13 were injured in January 2012.

Homemade weapons were used in this riot, which erupted after inmates from one area of the prison illicitly entered another one.