PHNOM PENH, Cambodia (AFP) — Cambodian authorities have arrested more than 1,000 people in raids on internet scam centres, police said Wednesday, as Prime Minister Hun Manet ordered a crackdown on cybercrime sweatshops.

The United Nations (UN) has described Southeast Asia as the “ground zero” of scam centres, where workers typically use romance or business cons to defraud social media users of an estimated US$40 billion annually.

Hun Manet issued a directive made public on Tuesday, telling law enforcement and the military “to prevent and crack down on online scams”, warning they risk losing their jobs if they fail to take action.

Over three days, authorities raided sites across the country, including in the capital Phnom Penh, the Thai border city of Poipet and the coastal city of Sihanoukville.

Just over 1,000 suspects were detained, according to police reports, which continued to be announced late on Wednesday night.

The vast majority of the reported arrests were foreign nationals — including at least 271 Indonesians, 213 Vietnamese and 75 Taiwanese.

Many of those freed from Southeast Asian scam centres say they were trafficked or lured there under false pretences.

Abuses in Cambodia’s scam centres are happening on a “mass scale”, Amnesty International said in a report published last month.

There are at least 53 scam compounds in Cambodia where organised criminal groups carry out human trafficking, forced labour, child labour, torture, deprivation of liberty and slavery, the report said.

In March, Cambodia deported 119 Thais — among 230 foreign nationals detained during raids on alleged cyber scam centres in Poipet.

The UN Office on Drugs and Crime warned in April that the scam industry was expanding outside hotspots in Southeast Asia, with criminal gangs building up operations as far as South America, Africa, the Middle East, Europe and some Pacific islands.