The detained Uzbek nationals were transporting drugs in the sole of their boots when they were caught at a police checkpoint with a total of 5.32 kilograms of heroin, RIA Novosti reported.

The former Soviet republic of Uzbekistan is a major transit country for drugs from neighboring Afghanistan, the world’s largest heroin and opium producer.

About 150 metric tons of heroin and 30 metric tons of raw opium are smuggled every year through Uzbekistan from Afghanistan with 75% of the drugs sold in Russia and Western Europe, according to official reports.