YANGON, April 25 (Xinhua) -- Three people, including a U.S. national and two locals, have been detained by the Myanmar's authorities for operating marijuana plantation in central Mandalay region, according to the Central Committee for Drug Abuse Control (CCDAC).

They were arrested by the authorities for growing marijuana in Myotha Industrial Park in Ngunzun township of the region after about 349,300 marijuana plants, 5,200 seedlings, 380 kg of marijuana seeds and 1.804 kg of marijuana oil were found during the authorities' inspection on Monday.

According to the authorities, about 8.1 hectares of land were leased from the Mandalay Myotha Industrial Development Public Company by two U.S. nationals for plantation.

Another U.S. national is at large, the police said.

They are being charged under Myanmar's Anti-Narcotic Drug and Psychotropic Substances Law.