Troops drove through the rough suburb of Santa Catarina, where assailants with Kalashnikov rifles gunned down a traffic police director on Monday, as well as the wealthy suburb of San Pedro Garza Garcia and the center of Monterrey.
On Monday, 150 state police officers in the metropolitan area of 3.2 million temporarily walked off their jobs to protest being forced to work overtime because of the deaths, arrests and resignations of their colleagues. Federal officials recently detained 18 officers in the state, Nuevo Leon, for allegedly working with drug cartels.
Nuevo Leon Gov. Jose Natividad Gonzalez said many of the municipal and state officers killed were "involved in organized crime."
"We are going through difficult moments. The security forces have been victims of the intense pressures of both corruption and threats," Gonzalez said.
President Felipe Calderon said Tuesday he will try to give provide resources and pay incentives for police who are on the front lines of his national offensive against drug cartels.
Nuevo Leon state police officers currently earn about US$760 (560 EUR) a month for the life-threatening job.
Nuevo Leon state police chief Antonio Garza said 91 officers were being trained to make up for the losses in the force and he said that police were enrolled in an anti-stress program to cope with their job conditions.
The Defense Department said it could not disclose how many soldiers were mobilized or how long they would remain in Monterrey, citing security reasons,
Drug violence has claimed the lives of police, soldiers and federal investigators across Mexico. Since taking office in December, Calderon has sent more than 24,000 soldiers and federal police to fight drug cartels from the Pacific resort city of Acapulco to the border city of Tijuana.