Police in Macau have arrested 26 people in raids in an operation to break up illegal World Cup gambling syndicates.

Officers in the Chinese city carried out two raids on the same hotel and said the arrests had brought down two syndicates.

Reporters were told that the first raid, carried out on Thursday, found a syndicate operating from three hotel rooms. People from mainland China, Hong Kong and Malaysia were detained.

Police found illegal bookmakers had been taking telephone and online bets from around the world, with some people having staked bets in the millions of dollars.

Suen Kam-fai, a Macau police spokesman, said: "Information indicates that this syndicate accepted bets before and after the matches kicked off -- that's why they needed a lot of manpower to take bets via the internet and telephone."

Officials said the arrests were "part of a continuing crackdown on illegal bookmaking in Macau."

Gambling is illegal in most of mainland China, but is allowed in Macau and also Hong Kong.

The authorities are concerned about high levels of illegal gambling surrounding the World Cup. Hong Kong police have set up a task force with their counterparts in Macau and believe criminal gangs are taking advantage of the tournament to rake in huge profits.