Mexico is sending thousands more federal troops and police to two states bordering Texas, in a further attempt to crack down on drug gangs.
Troops have been deployed across the country
Already, more than 20,000 personnel have been sent around the country.
The new move includes defence ministry, navy and security ministry forces. The navy will also patrol the Gulf Coast to try to intercept drug shipments.
President Felipe Calderon has vowed to fight the cartels said to be behind more than 200 deaths this year.
The latest troop and police deployment is to the states of Nuevo Leon and Tamaulipas.
Some of the troops will go to the city of Nuevo Laredo, which has been the scene of bloody turf wars between gangs in recent years.
Others are being sent to Monterrey, where 14 active or former police officers have been killed this year.
"We have begun a frontal struggle against organised crime that has no precedent in the country's history," Interior Secretary Francisco Ramirez Acuna told reporters on Sunday.
"We are recovering territory for our children," he said.
The anti-drug raids began on 8 December in the western state of Michoacan, and have since been expanded to several other states.
Officials say that in the raids, 3,873 hectares (9,566 acres) of marijuana, and 3,324 hectares (8,210 acres) of opium poppies have been destroyed.
Last year, more than 2,000 people died in cartel-related violence - some of the victims were tortured or beheaded.