MONTERREY, Mexico -- Hundreds of soldiers and federal agents are raiding casinos in this northern city, authorities said Saturday, two days after an arson attack on a gambling house killed 52 people and stunned a country.
Security forces had so far confiscated about 1,500 slot machines at 11 casinos in Monterrey and its surroundings and arrested three people, Mexico's tax agency said. It said the continuing operation was meant to verify whether casinos had paid taxes or introduced slot machines illegally.
Thursday's arson attack by gunmen was a macabre milestone in a conflict that the government says has claimed more than 35,000 lives since President Felipe Calderon launched an offensive against drug cartels in late 2006. Others put the death toll near 40,000.
The torching of the Casino Royale has raised questions over Mexico's regulatory controls for fast-spreading gambling houses.
Authorities have not been able to reach the owners of two companies pointed out as titleholders of the casino. Jorge Domene, security spokesman for Nuevo León state, said an order to appear before state police has been issued for owners of CYMSA Corp. and Vallarta Attractions and Emotions.
During the raids, which began Friday, about 700 soldiers, federal police and Treasury Department agents seized slot machines and put them in moving trucks.
Authorities did not say the raids were related to the arson. But one of the casinos searched was also registered under Vallarta Attractions and Emotions, according to the gaming unit of Mexico's Interior Department.
Federal police spokesman Juan Carlos Buenrostro said additional security forces were being deployed to this wealthy metropolis of more than 4 million people Saturday.
Jose Luis Benavides, a lawyer who specializes in Mexico's gambling law, said many casinos have connections to organized criminals who either intimidate or bribe authorities in order to remain open despite violations.
"They can be in operation because of legal protection, because of organized crime or because of corruption," he said.