The 50-day "Thunderbolt 07" operation in China, Hong Kong and Macau has broken 1,400 gangs, cracked 10,942 criminal cases and arrested 24,860 people, Xinhua news agency reported.

The crackdown focused on closing down online gambling, loan sharking, cross-border prostitution and drug dealing, said a spokesman with the Guangdong public security department on Wednesday, according to Xinhua.

Police also confiscated 159 guns, a huge stash of illegal drugs and more than 9,000 vehicles, he said.

"The crackdown aims to maintain social stability in Guangdong, Hong Kong and Macau, and to ensure a peaceful environment for the celebrations for the 10th anniversary of Hong Kong's return to the motherland," the spokesman said.