Mexican authorities say they have seized a record 37 tons of chemicals used illegally to create methamphetamine drugs. The Attorney General’s office announced Friday it was the largest seizure of the chemical precursors to methamphetamines in Mexico’s history. The chemicals were seized in two separate raids. Twenty tons were intercepted at a Pacific Ocean port in the city of Manzanillo, while 17 tons were taken at a customs post at Nuevo Laredo, just across the border from the U.S. state of Texas. The U.S. government says Mexico is a leading source of illegal methamphetamines. Since taking office in 2006, Mexico’s president Felipe Calderon has waged war against the drug trade and has deployed tens of thousands of troops in the crackdown.