At least 26 people have been killed in a clash of armed groups in northern Mexico, authorities said.

Fifty-two inmates have been killed and 12 injured in a brutal fight between two rival factions at a prison in northern Mexico.

Mexico’s old rulers have claimed victory in a presidential election, ending 12 years in opposition after a campaign dominated by a sputtering economy and rampant drug violence.

A prison riot in northern Mexico left about 20 people dead today.