The death toll from Thursday's arson attack on a casino in the northern Mexican city of Monterrey now stands at more than 50 people.

Nuevo Leon Governor Rodrigo Medina told the Televisa network that 53 people were killed in the attack on the Casino Royale. Monterrey is the capital city of Nuevo Leon.

Witnesses say several gunmen burst into the casino and doused the premises with gasoline before setting it on fire. Many of the victims were found inside the casino's bathrooms, where they fled to escape the gunmen.

Mexican President Felipe Calderon condemned the attack as an “abhorrent and barbaric act of terror” in a message on Twitter.

Casinos and other businesses have been targeted by drug cartels demanding protection money.

Drug-related violence has been on the rise in Monterrey, a city of four million people once seen as a safe and prosperous city.

More than 41,000 people have been killed since Mr. Calderon launched a crackdown against the country's drug cartels beginning in late 2006.