HO CHI MINH CITY, June 6 (Xinhua) -- Vietnamese customs have recently detected four cases of importing Khat leaves which contains cathinone, classified by Vietnam as a narcotic drug, from Africa via southern Tan Son Nhat international airport, local media reported Monday.

The customs at the airport in Ho Chi Minh City have confiscated over 1.2 tons of Khat leaves recently, including 336 kg on Sunday,  newspaper Hai Quan (Customs) reported.

If the 1.2 tons of Khat leaves had been re-exported to the United States or some European countries, their owners would have gained estimated 2.2 million U.S. dollars, said the local newspaper.

Khat (Catha edulis) is a flowering plant native to the Horn of Africa and the Arabian Peninsula. Among communities from these areas, khat chewing has a history as a social custom dating back thousands of years.

Khat contains a monoamine alkaloid called cathinone, an amphetamine-like stimulant, which is said to cause excitement, loss of appetite and euphoria.   In 1980, the World Health Organization (WHO) classified it as a drug of abuse that can produce mild-to-moderate psychological dependence, although WHO does not consider khat to be seriously addictive.

It is illegal or a controlled substance in many countries, while its production, sale, and consumption are legal in some African nations.