Curbs tightened ahead of Games Five of the six Olympic cities on the mainland - including Shanghai and Beijing - have in effect suspended the issuing of business visas to foreigners until after the Games. In the latest entry restriction introduced ahead of the Olympics, authorities in the five cities have stopped providing invitation letters, also known as notification letters, which are required in support of applications to visit the mainland for business visits, market research and training. The move has shocked businesspeople with interests on the mainland, some of whom say it could cost them millions of dollars. The Shanghai Foreign Economic Relations and Trade Commission, the municipal authority dealing with foreigners' visa applications, posted a notice on its website on Monday saying all applications for notification letters would be suspended until mid-September. Authorities in Beijing and three other cities that will co-host the Games - Qingdao, Shenyang and Qinhuangdao - said similar restrictions had been imposed there. A Hong Kong businesswoman, who wished to remain anonymous, said her company had planned a large textile exhibition in Shanghai early in September, but 500 to 600 overseas guests invited by the company would not be able to attend. 'I was very shocked when I learned of the restriction on invitation letters. I've really no idea about what to do next,' she said, estimating her company would lose business worth millions of dollars. Shanghai, which will host some Olympic soccer matches, said in its notice that the new restriction was required by 'the superior authorities' in an effort to 'make sure the Olympic Games will run smoothly and to sustain social stability during the Games'. Exemptions would only be given to work-visa applicants and those who needed to go to Shanghai in 'emergencies'. In Beijing, an official at the Municipal Bureau of Commerce said similar restrictions had been in place for two weeks. All applications for invitation letters for business visas would be delayed and dealt with after September 20. 'We may still consider those coming to China to sign contracts. If that is the case, the applicant should first show us the original copy of the contract,' he said. Authorities in Qingdao, Shenyang and Qinhuangdao confirmed similar curbs on the invitation letters. But an official in Tianjin, where preliminary soccer matches will also be played, said there were no such restrictions. British Chamber of Commerce executive director Christopher Hammerbeck said the tightening measure would certainly have a short-term negative impact on business activities. 'Clearly, [the central government is] frightened of something,' he said. Over the past few months, it had turned down multiple-entry visa applications from several chamber members. 'The uncertainties [of doing business in China] have escalated,' he said. The new chairman of the Hong Kong General Chamber of Commerce, Andrew Brandler, said there would be an impact from the visa restriction, but it was not 'fundamentally a problem'. 'There is a lull in business activity during the summer months and the Olympics would have already been factored into most business trips to Beijing during that time,' he said. In March, Beijing introduced a series of entry restrictions, including the suspension of multiple-entry visas for foreigners, and requiring many to return to their home countries to apply for work visas instead of doing so in Hong Kong. Tourists are required to show advance hotel reservations and return-flight bookings upon submitting visa applications.