More than 1,000 people have been arrested in the first dozen days of the government’s drug crackdown, in what critics have labelled a heavy-handed campaign that could have unintended consequences.

The scheme had netted 1,055 at the close of its 11th day, officials said, with roughly half of those arrested being drug users. National Police anti-drug chief Mok Chito yesterday said that although, by law, all drug users should see jail time, the government was adopting a new philosophy that included sending more than 300 purported users to compulsory rehabilitation centres, which have long been criticised for a litany of rights abuses.

He explained the 487 alleged users were divided into “light” and “heavy”. For light users, if parents vouched for their child or they agreed to get voluntary drug treatment, they would be sent to one of 200 voluntary treatment clinics across the country. If they were “strong-headed” heavy users, they were sent to one of the Kingdom’s 13 rehabilitation centres.

“For those who are [both] heavily addicted and who pose a danger to others, we just send them to prison.”

As of Wednesday, at least 300 people had been sent to rehabilitation centres, while more than 90 alleged users were imprisoned, along with 561 alleged traffickers. “Community-based treatment is the number one for effectiveness, but no one voluntarily goes to get treatment by themselves,” he said, adding that those busted were being separated from the general population in prisons.

Ministry of Health undersecretary of state Chhum Vannarith said he was “optimistic” about the campaign because it was paired with education.

“The problem in Cambodia nowadays is that parents hide the fact their children are addicted to drugs. They feel discriminated against, so they try solving the problem by themselves, away from the community,” he said.

Choub Sok Chamreun, executive director of NGO Khana, said that while he supported the campaign particularly its focus on rehabilitation and drug treatment he urged them to let NGOs help ensure “the rights of drug users are respected”. “Of the drug treatment services in Phnom Penh, we learned these services are not yet meeting the needs of the drug users,” he said.

Sok Chamreun said he was also concerned about the fate of drug-users who through arrest or fear – could interrupt their treatment plans.

“In the last 12 days of the campaign, 15 clients who used to receive methadone treatment stopped it, and we don’t know where they are,” he said.

“We worry they could be hiding and stop going out daily to their methadone clinic, and that can increase symptoms and link to overdoses, which can be life-threatening.”

Pointing to officials’ seemingly arbitrary distinction between “light” and “heavy” users, drug consultant David Harding yesterday said police lacked training to measure drug dependency, adding that compulsory treatment was “99 percent ineffective”, and that mass arrests were not the solution.

“The only thing it will do is drive dealers underground, which will make it more difficult for people to source their drugs, which means they take much bigger risks,” he said. “We could be seeing deaths from overdoses.”