The Chinese government has revealed the recent tightening of restrictions on visas is part of its Olympic security measures. China's stricter interpretation of visa rules has led to concerns that thousands of foreigners may be forced out and complaints from businessmen that they cannot get in. Daniel Schearf reports from Beijing.

China's foreign ministry finally gave a clear explanation as to why visas to China have suddenly become difficult to obtain.

Foreigners looking to renew their previously widely available business visas are being told they can no longer purchase the multiple-entry one-year visas.

There are also reports of foreigners having to show airline tickets and proof of advanced hotel booking as additional documentation.

Foreign Ministry spokesman Qin Gang answers reporters' questions in Beijing, 06 May 2008

China's Foreign Ministry spokesman Qin Gang said the government is not suspending all multiple entry visas. But, he revealed it is adopting stricter procedures to ensure a safe environment during the Beijing Olympics.

He says the current visa arrangements are following the usual practice of the Olympics and the hosting of large-scale international contests as well as China's own laws and relevant regulations.

For some weeks the Chinese government refused to give a clear explanation for the changes, though stepped-up security for the Olympics was widely suspected to be the reason.

The Chinese government has yet to make the new requirements clearly known or widely circulated, upsetting many in the foreign business community.

In April, the European and American Chambers of Commerce in Hong Kong sent strongly worded letters of complaint to Beijing after businessmen had their visa applications rejected.

Despite the tighter regulations, Qin said China still welcomed foreigners to China for study, work and travel. He said China's visa policy was much more relaxed than many countries.

For example, he said unlike some countries, they do not require finger prints or retinal eye scans - a clear reference to security measures in the United States.