Thai police said Wednesday they have arrested more than 1,000 people, including four foreigners, in a crackdown on illegal betting during the World Cup.

The arrests come amid a wider blitz on gambling by the new junta in a bid to "uphold social order" in Thailand, where betting is largely banned with locals restricted to gambling only on the state lottery or at a handful of horse racing meetings.

"Since the World Cup began we have arrested 1,023 people for illegal gambling on matches, the majority of whom are punters," said Police Major General Chantavit Ramsut.

Police also seized betting slips worth $525,000 during raids since the World Cup kicked off in Brazil on June 12, he added.

Early on Tuesday police and military officials arrested four foreign nationals -- the first non-residents captured so far in the crackdown -- on suspicion of illegal betting at a sauna in downtown Bangkok, Chantavit said.

Three of the suspects -- one from Macau national and two from Hong Kong -- were believed to be bookmakers.

The fourth, a Malaysian, was placing bets at the time of his arrest, according to Chantavit.

If convicted of illegal gambling the suspects, all in their fifties, face a $60 fine and two years in prison. They will also be charged with working in Thailand illegally, said Chantavit.

The crackdown on organised crime by the junta -- which seized power on 22 May -- has seen raids on underground casinos, dozens of arrests and access to a number of online gambling sites blocked.

According to police figures, nearly 3,800 people were arrested across Thailand for gambling during the last World Cup in 2010.

Around $4 million was seized in cash and betting slips and frozen in bank accounts.