Mexican soldiers and federal police sent to restore order in Michoacan state have discovered 1,795 marijuana fields in the past week and seized or destroyed marijuana worth about $8.2 million, security officials said Monday.

Officials estimate the raids cost the drug cartels as much as $626 million, counting not only the value of the destroyed plants but also the drugs that could have been produced with opium poppies and marijuana seeds seized in the raids, the army said.

Federal authorities on Sunday announced they had captured suspected drug cartel boss Elias Valencia, the most significant arrest since President Felipe Calderon sent 7,000 military troops and federal police last week to the western state terrorized by drug gangs that have carried out beheadings and other brutal killings.

"In this battle, we will not spare any efforts or resources to ensure the peace and establish minimum conditions of law and order," the country's top security official, Interior Secretary Francisco Ramirez Acuna, told reporters Monday.

Ramirez Acuna said the operation aims "to end the impunity of criminals that placed at risk the peace of all Mexicans."

Calderon, who took office Dec. 1 after being narrowly elected on a law-and-order platform, has vowed to battle against drug violence that has claimed more than 2,000 lives nationwide this year.

Officials blame the violence in Michoacan on a battle between the Valencia and Gulf cartels over lucrative marijuana plantations and smuggling routes for cocaine and methamphetamine to the United States.

Soldiers and police have found drug fields covering 587 acres in Michoacan's verdant hills, Defense Secretary Guillermo Galvan Galvan said.

Authorities have detained about 45 people, including Alfonso Barajas, accused of being the main operator for the Gulf drug cartel in Michoacan, and Jesus Raul Beltran, accused of being a leading member of the Sinaloa drug cartel. Valencia, a suspected head of the Valencia cartel, was arrested along with four other people Friday at a mountain ranch near the town of Aguililla in Michoacan state.

In other matters, prosecutors announced the arrest in central Hidalgo state of Alberto Barragan, who had allegedly kidnapped 21 people and lopped the fingers off some of his victims.