Police have broken up 600 online soccer gambling groups and arrested more than 810 gamblers since the World Cup began on June 11, the Ministry of Public Security said on Thursday.

Among those arrested, 65 were from Hong Kong, Macao and Taiwan, as well as from countries like the Philippines and Malaysia, the ministry said in a briefing.

Authorities seized gambling funds worth about 50 million yuan ($7.3 million) in the crackdown, the ministry said.

"After the 2010 World Cup in South Africa started, local police struck out against online soccer gambling to prevent gambling groups from taking advantage of the event to expand their rackets," said Gu Jian, a senior official with the ministry's online security bureau.

Before the opening of the World Cup, police had already detained 3,600 people during a nationwide crackdown on online gambling starting January, ministry figures showed.

In a separate case, Hong Kong and mainland police reportedly cracked a large cross-border illegal soccer gambling syndicate, seizing betting slips worth more than $1 billion.

Officers arrested 93 people from Hong Kong and the mainland in a joint operation late on Wednesday, Hong Kong-based broadcaster RTHK reported.

Police said the syndicate mainly received online and telephone bets through more than 400 bank accounts, the largest number of accounts involved in a local illegal soccer betting case, Cable TV Hong Kong reported.

"We identified a trend that the bets were mainly placed via the Internet - same as in other countries or regions," a police spokesman told the broadcaster.

The Ministry of Public Security said in a release last month that China is still facing a "very grim" situation in controlling online gambling activities.

"The root of online gambling hasn't yet been eradicated and some money flows still run unchecked," it said.

Even with the police crackdown on gambling, underground soccer betting bookies can always use Internet proxies, VPN and other Web devices such as overseas gambling websites to bypass any official attempt to block illegal online activities, a Beijing soccer gambler, who did not want to be named to protect his identity, told China Daily.

"It's almost impossible to find and arrest them all. There are too many of them and they resurface all the time. Gamblers prefer their higher gambling return rates to lotteries," the gambler said.

At Thursday's conference, the Ministry of Public Security said police had also broken up a number of groups that facilitate gambling activities, including those providing advertisements as well as those operating platform and payment services.

Similarly, the ministry said police have worked with banks and Internet supervisory bodies to clean up gambling websites, servers and links, and to cut off third-party payment services for websites running gambling activities.

But Wang Xuehong, executive director of the China center for lottery studies at Peking University, said the problem can only be solved when the country makes lotteries "more attractive" in terms of variety and returns.