At least 16 inmates have been killed and five more were wounded during a riot in a Mexican prison.
The riot broke out at around 2.30pm local time on Tuesday in Cieneguillas state prison in Zacatecas central Mexico.
The prison was brought under control by 5pm, according to a statement from the state's security agency.
Fifteen of the victims died at the prison and one died later in hospital.
One prisoner was detained with a gun still in his possession and the other three were found inside the prison, the statement said.
Zacatecas state security secretary Ismael Camberos Hernandez said authorities confiscated four guns they believe were introduced to the prison during visits on Tuesday.
He said the prison had been searched for weapons on Saturday and Sunday and no guns were found.
Mr Camberos said not all of the victims died from gunshot wounds.
Some were stabbed and others were beaten with objects.
He added that no guards or police were wounded..
