SOFIA, Feb. 5 (Xinhua) -- Bulgarian customs have seized 32 kg of ecstasy at the Kalotina checkpoint near the country's border with Serbia, officials said here on Monday.

The illicit drug was discovered on Sunday evening after a truck with Turkish registration carrying flowers from the Netherlands to Turkey went through an X-ray examination, the National Customs Agency (NCA) and the country's Prosecutor's Office said in a joint statement.

The driver of the vehicle, a Bulgarian citizen, was arrested on the scene, the statement said.

Ecstasy or methylenedioxy-methamphetamine (MDMA) is a synthetic drug that alters mood and perception.

Bulgaria is a key transit route for drugs usually smuggled from Asia to Europe. Last year, the amount of drugs and precursors seized by the NCA reached a total of 7,572 kg, 16,128 liters and 11,699 tablets, the agency said in its annual report.