Authorities in a southern Mexican state popular with tourists reported Monday that 55 bodies -- more than double the number initially thought -- had been recovered from an abandoned silver mine apparently used by drug gangs as a mass grave.

Evidence of the bodies, apparently the victims of drug gang violence, was discovered last week and officials said at the time that there appeared to be up to 25 bodies in the mine. However, during the week, additional bodies were found and over the weekend, 55 had been recovered, said Albertico Guinto Sierra, the attorney general for Guerrero state. The body count was announced Monday in a statement on the state government’s Web site.

Three of the bodies were mummified and two had been reduced to skeletons, the statement said, making it unclear how long the mine, called San Francisco Cuadra, had been used as a mass grave. The federal police said last week that a suspect in a case involving organized crime had told the authorities about the mass grave. At least 15 people have been detained in the case, The Associated Press reported Monday.

Guerrero is plagued by drug violence among rival gangs, and marked by brazen attacks on the police and soldiers engaged in a crackdown on traffickers.