Chinese criminals running cryptocurrency scams in Southeast Asia are targeting Filipinos to work for them because of their English language and computer skills, a Philippine foreign ministry official said Monday.

Filipinos were "prized" targets for scam networks operating in Myanmar, Laos and Cambodia, said Eduardo de Vega, acting undersecretary for migrant workers affairs at the Department of Foreign Affairs.

De Vega said efforts to repatriate Filipinos sucked into the scam activities were ongoing, with more than 100 brought home since last year.

The latest group arrived in Manila on Monday. Four men, all in their 30s, had been trafficked into Myanmar for "less than two months" where they were held in compounds, de Vega told AFP.

The men were in Dubai when they were recruited online to work as "customer support representatives" in Thailand, the ministry said.

When they arrived in Bangkok, they were taken to the western Thai city of Mae Sot and ferried across the border into Myanmar "rebel territory", de Vega said.

There they were "forced to trick individuals into investing in cryptocurrency", the foreign ministry said in a statement.

Myanmar's rugged borderlands are home to a patchwork of ethnic rebel groups and military-aligned militia that have fought each other for decades over territory, lucrative timber and jade resources, and the drug trade.

Typically, Filipino recruits would pretend to be women and develop online relationships with their targets, usually a Westerner, de Vega said.

They receive a wage and get a share of the profits, but are subjected to "corporal punishment" if they do not scam enough people, he said.

Four Filipino women in their 20s, who were detained in Myanmar for illegally entering the country from Thailand a few weeks ago, also returned to Manila on Monday.

They had claimed to be tourists, de Vega said.

Around 50 to 70 Filipinos are believed to be still working for Chinese scammers operating in Myanmar, he added.

There were another 50 Filipinos working for cryptocurrency scams in Cambodia and 50 in Laos, de Vega estimated.

He said "at least 119" Filipinos had been brought home since last year.

"We are slowly repatriating them, but some are not asking to be repatriated," de Vega said.

"But if there's a relative who contacts us with an SOS, we'll do it."

An AFP report last year found people from around Asia -- including from Vietnam, the Philippines, Thailand, Malaysia, China, Taiwan, Hong Kong, Bangladesh and India -- have been pulled into similar operations in Cambodia, some trafficked and beaten by scam operators.

De Vega said the Philippine government had repeatedly warned Filipinos against bypassing official employment channels when looking for work abroad.

"We have to stop these Filipinos that get tricked," de Vega said.

"It's not true that you can arrive as a tourist and then get work... if they ask for computer experts or customer service, you'll probably be asked to be a scammer."