SINGAPORE - A surge in the number of new psychoactive substances (NPS) abusers drove up the overall arrest rate for drug abusers here last year.

A total of 343 NPS abusers were nabbed, compared to just one the year before, the Central Narcotics Bureau (CNB) said on Monday (Feb 25) in its annual report.

NPS overtook heroin as the third most commonly abused drug among first-time abusers and, similarly, overtook cannabis as the third most commonly abused drug among all users.

The amount of drugs seized last year was estimated to have a total street value of about $6.65 million, a slight increase from about $6.63 million the year before.

NPS produces similar effects as controlled drugs such as cannabis, cocaine, Ecstasy, methamphetamine or heroin. In May last year, 25 NPS were listed as Class A controlled drugs, and dealing with such drugs is punishable under the Misuse of Drugs Act (MDA).

Methamphetamine was the drug of choice for most new abusers in Singapore last year, with cannabis in second place. Methamphetamine and heroin were the top two drugs for all users, comprising 62 per cent and 20 per cent of those arrested respectively.

Among offenders, 478, or 14 per cent, of them abused more than one type of drug.

"In particular, the increase in NPS abusers was a result of sustained enforcement efforts targeting NPS abuse and enhancements in detection capabilities," the CNB said.

CNB director Ng Ser Song has described the global and regional drug situation as "worrying".

He noted that the production and trafficking of methamphetamine had reached "alarming levels", and the market for NPS was continuing to evolve.

"There is also a push in some countries for alternative, liberal drug policies," he said.

Data from last year's United Nations Office on Drugs and Crime (UNODC) World Drug Report showed that South-east Asia is one of the world's largest methamphetamine markets, and the second largest opium and heroin market.

Close proximity to such large scale drug production regions places Singapore at a high risk of being a target for drug trafficking syndicates, CNB said.

Against this challenging backdrop, Mr Ng said the CNB mounted intensive enforcement operations last year and dismantled 26 drug syndicates.

Together with the police and Immigration and Checkpoints Authority, the agency conducted 19 island-wide operations targeting drug traffickers and abusers, and 1,575 operations to foil drug smuggling attempts at the checkpoints.

Given the transnational nature of drug trafficking, cross-border collaborations remained crucial in tackling the issue. Last year, the CNB conducted 19 joint operations with its international counterparts.