Bulgarian customs officials say they have seized 191 kilograms (420 pounds) of heroin found in a truck entering Bulgaria from Turkey.
Officials valued the heroin at 6.3 million euros ($7.4 million).
The national customs agency said on Friday that the drugs were found in a Turkey-registered truck at a checkpoint on the Turkish border. It was carrying construction materials and was bound for Belgium.
Customs chief Georgi Kostov said the heroin was hidden in 95 factory-sealed bags.
The driver, a Turkish citizen, was detained and could face up to 15 years in jail, if convicted on drug trafficking charges.