Mexican officials seized 53 tons of cocaine in 2007 and only 10 tons last year, according to a report Tuesday from the International Narcotics Control Board, which monitors global drug-control agreements.

Antonio Mazzitelli, representative in Mexico of the U.N. Office on Drugs and Crime, said traffickers are diverting their cocaine operations elsewhere, but he cautioned that seizures of drugs produced inside Mexico, like methamphetamine and marijuana, remain stable.

The government of President Felipe Calderon has funneled tens of thousands of federal police and troops into a six-year fight against drug cartels. The pressure has driven a rise in deadly battles for turf between cartels.

The government pressure and fighting among cartels appear to be increasing the risks involved in moving cocaine the long distances from South America through Mexico and into the United States, Mazzitelli said.

Seizures of cocaine in Central America continue to be very high, which might mean that trafficking is increasingly bypassing Mexico and moving along less difficult routes like those through the Caribbean, he said.

"More law enforcement presence on the territory, increased control on the U.S. border, plus infights among criminal groups make moving large consignments of cocaine quite risky in economic terms," Mazzitelli said.

Earlier, Mexico's army said soldiers had found 120 plastic helmets purportedly worn by members of the cult-like Knights Templar drug cartel during initiation ceremonies for new members.

The cartel adopted the name of monastic warriors who fought during the Crusades, but the helmets appear to be more styled on headgear in ancient Greece.

Such helmets are often worn in rural Mexico by people portraying Roman centurions during Easter-week passion plays.

The army said soldiers found the helmets late last week in a rural area in western Michoacan state.

The Knights Templar cartel appeared in 2010. It claims to protect Michoacan and defend ethical principles, but in fact engages in drug trafficking, killings and extortion.