BANGKOK (AP) -- Thailand has started banning the sale of cannabis to those without a prescription, three years after becoming the first country in Asia to decriminalize the plant.

The new order, signed by Health Minister Somsak Thepsutin earlier this week, came into effect Thursday after it was published in the Royal Gazette. It bans shops from selling cannabis to customers without a prescription and reclassifies cannabis buds as a controlled herb.

The order cited a punishment from the 1999 Act of Protection and Promotion of Traditional Thai Medicine Wisdom, in which a violation would result in a maximum one-year jail term and a 20,000-baht ($614) fine.

The Department of Thai Traditional and Alternative Medicine, in charge of enforcing regulations related to cannabis, held a meeting Friday with officials across the country to prepare them for the change.

The move to decriminalize in 2022 had boosted Thailand's tourism and farming industries, and spawned thousands of shops.

But the country has faced public backlash over allegations that a lack of regulation made the drug available to children and caused addiction.

Treechada Srithada, spokesperson for the Health Ministry, said in a statement Thursday that cannabis use in Thailand would become "fully for medical purposes."

She said shops that violate the order will be closed and the ministry will also tighten requirements for approval of a new license in the future. She said there are curently 18,000 shops that hold a license to sell cannabis.

The ruling Pheu Thai Party previously promised to criminalize the drug again, but faced strong resistance from its former partner in the coalition government, the Bhumjaithai Party, which supported decriminalization.

Bhumjaithai quit the coalition last week over a leaked phone call between Prime Minister Paetongtarn Shinawatra and former Cambodian leader Hun Sen.

The move to restrict cannabis sales came after officials last month revealed that cannabis smuggling cases involving tourists had soared in recent months. Somsak told reporters Tuesday he would like to relist cannabis as a narcotic in the future.

Thailand's Office of the Narcotics Control Board said a study conducted by the agency last year found the number of people addicted to cannabis had spiked significantly after it was decriminalized.

A group of cannabis advocates said Wednesday that the change in regulations was politically motivated and that they will rally at the Health Ministry next month to oppose the change and any attempt to make it a criminal offense again to consume or sell cannabis.