The Ministry of Public Security is stepping up efforts to work with some countries in Africa and Southeast Asia to tighten visa issuance.

The move is aimed at preventing Chinese mainland travelers from staying illegally in Hong Kong and Macao in transit to third destinations.

"We will work with the Ministry of Foreign Affairs to communicate with the embassies of some African and Southeast Asian countries for them to monitor their issuing of visas," a senior ministry official told China Daily.

The official, from the public security ministry's entry and exit administration bureau, did not want to be named.

Some travel agencies in Shenzhen and Zhuhai in Guangdong province, just over the border from the Hong Kong and Macao special administrative regions, help travelers to obtain visas easily for countries in Africa and Southeast Asia, the official said, citing Thailand as an example.

The visas allow travelers from the mainland to enter Hong Kong and Macao for transit purposes, but they stay there illegally instead, he said.

"After charging the passengers 100 yuan ($16) to 1,000 yuan each, these travel agencies take their passports to embassies to apply for visas and the embassies quickly issue them," he said.

China Central Television reported that some travel agencies in Shenzhen were helping mainland travelers to obtain documents to enter and stay in Hong Kong although their travel permits to Hong Kong or Macao had expired.

Other travel agencies might cancel flight bookings once their customers entered Hong Kong, the report said.

CCTV recorded one travel agency employee in Shenzhen saying: "You pay only 100 yuan and I will help you apply for a visa to leave for another country. I'll provide you with a fake air ticket to help you get through the border checks."

Hong Kong regulations allow visitors holding passports issued on the mainland, who tell border police they are in transit to another destination, to stay in the special administrative region for seven days, providing they produce documents such as visas and air tickets.

But those who do not leave within seven days can be blacklisted and refused re-entry to Hong Kong or even face criminal charges.

Those convicted can face up to 14 years in prison and be fined up to HK$150,000 ($19,300). The same regulations apply in Macao.

The latest figures from Hong Kong's Immigration Department show that an increasing number of mainland travelers arriving in the city without the proper documentation are pretending to be in transit.

In the first three months of the year, 1,632 such travelers were refused entry, compared with 2,940 for all of last year.

This week, Hong Kong immigration officers detained 23 mainlanders for falsely claiming to be in transit, Xinhua News Agency reported. Three of them were sent to prison for two months for making false statements.

The Thai embassy in China said it is taking "this matter seriously to ensure that our visas are not misused".

"The issuance of visas, and other consular matters, are matters of national security, thus the embassy has clear guidelines and necessary requirements on the processing of visa applications," it said in a statement.

"We are ready to cooperate with the Chinese authorities on this matter," it added.

In recent years, there had been a number of travelers from the mainland whose permits for Hong Kong and Macao had expired but who did not apply to public security agencies in their hometowns for new ones, China's Ministry of Public Security said. Some of these travelers engaged in illegal activities in Hong Kong or gambled in Macao casinos, it said.

The senior ministry official said many illegal visitors resorted to prostitution or other criminal activities.

Ma Lin, a lawyer at the Yingke Law Firm in Beijing, said Macao police should also intensify efforts to crack down on illegal visitors.Jamaica welcomes Chinese visitors with visa-free policy

Zhao Yanrong contributed to this story.

zhangyan1@chinadaily.com.cn