Guests checking into hotels in the capital of South China's Guangdong province are now required to present their identity cards, as the police on Tuesday launched a crackdown on illegalities at entertainment venues ahead of the Asian Games in November.

More than 1,200 people in charge of security at Guangzhou's nightclubs, bars, sauna parlors and hotels signed documents, pledging to run their businesses with honesty.

They promised to prevent security incidents, major criminal cases, prostitution, gambling, drug consumption and trafficking, and to register the IDs of hotel guests.

Luo Zhenhui, deputy director of the city's public security bureau, warned people against trying their luck.

"The checks at entertainment venues and hotels will be more stringent than ever before and any illegality will be dealt with very seriously.

"Some (entertainment venues and hotel) think their business cannot thrive without prostitution and drugs. But there is no chance for prostitution, gambling and drug-related crimes at such venues in Guangzhou now," Luo said.

Since June 18, the Guangzhou police have been religiously doing rounds of the city's hotels, checking the registration and transmission of ID information of temporary hotel guests, and will continue the practice until the end of this year, said Liu Wenhuang, an official with the city's public security bureau.

A hotel receptionist surnamed Huang said he had to refuse five guests recently because only one of them could produce a valid ID.

The Guangzhou police busted 10 entertainment venues and hotels involved with drugs and 51 with prostitution in the first half of this year, arresting 146 people.

Some entertainment venues were found open after 2 am, which is prohibited under the current regulation, and some were overcrowded, posing a danger to people's safety.

Violence at entertainment venues is the second highest reason for contacting the police in the city.

Guangzhou is only one of the cities in the country that has cracked the whip on entertainment venues and hotels this year.

Many popular venues in Beijing, Chongqing and Nanjing, Jiangsu province, have also been punished for illegalities recently.

The crackdown in those cities had won wide acclaim from the public, said Huang Ming, vice-minister of public security, in a teleconference on Tuesday.

In less than a week since the opening of the World Cup in South Africa, the police had blocked 1,461 overseas gambling websites.

In the next stage, the Ministry of Public Security will check and punish those involved in the crimes with strict measures, Huang said.