Turkish police seized 40.3 kilograms (88.8 pounds) of heroin in the country's eastern Ağrı province, authorities announced on Sunday.

The heroin was confiscated from a vehicle that was stopped at a checkpoint in the city center of the province, said the source on condition of anonymity due to restrictions on speaking to the media.

The heroin, hidden in 80 packs, was seized in an operation assisted by sniffer dogs and four suspects were arrested.

Turkey has been successful in seizing drugs, but the country still remains a popular route for drug smuggling to Europe.

Last June, Turkey conducted its largest narcotics operation and detained 67 people in "Operation Swamp," which targeted a gang with international connections in Brazil and the Netherlands.

The suspects caught in the operation were behind the shipments of drugs seized by authorities on various dates, from tons of heroin captured in 1993 to more than 18 tons of cocaine seized in 2012, as well as 20 tons of heroin and ecstasy pills captured aboard a vessel in 2016.

According to a report by the United Nations Office on Drugs and Crime (UNODC), Turkey seized 62% of heroin and morphine in the region outside of Asia. Turkey accounts for the bulk of heroin and morphine seized in eastern and southeastern Europe at 95%.