Jakarta (AFP) - Handcuffed and wearing black masks, a Hong Kong man accused of being a drug lord and his gang were Tuesday forced to publicly burn a $136-million stash of crystal methamphetamine after their arrests in Indonesia.

Wong Chi-ping and several other suspects were paraded in front of the media, before throwing packets of the drugs into the flames of a giant incinerator in a town just outside the capital Jakarta.

"The drugs are garbage, that's why we are burning them," national narcotics agency chief Anang Iskandar told reporters. A total of 862 kilograms (1,900 pounds) of drugs were burnt.

The man alleged to be the gang's kingpin, along with three other Hong Kong residents, a Malaysian and four Indonesians, were arrested earlier this month, following a three-year investigation into a global syndicate.

They could all be sentenced to the death if found guilty of drug trafficking.

Indonesia enforces some of the world's toughest anti-drugs laws and has been stepping up its campaign against narcotics under new President Joko Widodo, who is a strong supporter of capital punishment for traffickers.

Earlier this month, six drugs offenders -- including five foreigners -- were put to death by firing squad.

"Indonesia has declared war on drugs. We want to save the future generation, our children and grandchildren," said Security Minister Tedjo Edhy Purdijatno at Tuesday's event.

The drugs -- concealed in coffee packets -- were around 97 percent pure, and the syndicate was wanted in more than seven countries, including China, the Philippines, Malaysia and Singapore, said Indonesian narcotics agency official Deddy Fauzi Elhakim.

Describing the capture of the drugs gang as "really spectacular", he said authorities had enough evidence to charge all nine men with drug smuggling.

"(Wong) will definitely be sentenced to death. This is an extraordinary crime," he added.

Indonesian authorities had been monitoring Wong since 2012. He was caught after a fishing boat brought the drugs to Jakarta, and he tried to sell them on.

Crystal methamphetamine, commonly known as "ice", is a highly addictive drug.