Six police officers have been arrested in Mexico in connection with the murder earlier this week of the mayor of a northern town.
The body of Edelmiro Cavazos was found bound and dumped on a road on Wednesday, three days after he went missing from his home in Santiago.
It is believed Mr Cavazos may have been killed for his efforts in ridding the local police of corrupt officials.
More arrests are likely to result from the investigation into Mr Cavazos’ death.
The killing has caused outrage in Mexico, with President Felipe Calderon vowing to ‘redouble’ his crackdown on the gangs.
More than 28,000 people have died in the confrontation between the gangs and security forces since the end of 2006, when President Calderon launched his controversial military operation against organised crime.
Officials said Mr Cavazos, who was known for his tough stance against organised crime, had been forced from his home by armed men wearing out-of-date federal police uniforms. No ransom was demanded.
His bodyguard, the only witness to the kidnapping, was found bruised but otherwise unhurt on a road on the outskirts of town shortly after the abduction.
Santiago is in the state of Nuevo Leon, which borders the US state of Texas.
