BEIJING (REUTERS) - China on Wednesday (Aug 3) suspended exports of natural sand to Taiwan and halted imports of citrus fruit and certain fish products from the self-governed island as US House of Representatives Speaker Nancy Pelosi visited Taiwan in a trip condemned by Beijing.

In a warning salvo ahead of Mrs Pelosi's visit, Chinese customs had suspended imports from 35 Taiwanese exporters of biscuits and pastries since Monday.

In January-June, China's imports from Taiwan reached US$122.5 billion (S$169.1 billion), up 7.3 per cent from a year earlier, Chinese customs data showed. Top imported goods included integrated circuits and electronic components.

Natural sand

China's commerce ministry said exports of natural sand - widely used for construction and in concrete - to Taiwan were suspended from Wednesday.

Such a move was based on laws and regulations, the ministry said, without elaborating.

In March 2007, China halted exports of natural sand to Taiwan due to environmental concerns. The ban lasted for a year.

According to Chinese official data, more than 90 per cent of Taiwan's natural sand imports came from China in 2007.

Fruit and fish

China also halted imports of citrus fruit, chilled white striped hairtail and frozen horse mackerel from Taiwan from Wednesday, a suspension which it said was due to pesticide residue found on citrus fruit, while traces of the novel coronavirus were detected on the packaging of some frozen fish products in June.

China's top food and agricultural imports from Taiwan include seafood, coffee, dairy products, beverages and vinegar.

In January-June, China's biggest agricultural and food import items from Taiwan were fish and other aquatic invertebrates, reaching 399 million yuan (S$82 million).

Earlier this year, China suspended imports of grouper fish from Taiwan, saying it had detected banned chemicals.

Last year, Beijing also suspended pineapple, sugar apple and wax apple imports from the island, citing pest concerns.

Two foundations

China also vowed to take "disciplinary actions" against two Taiwan foundations which it claimed had aggressively engaged in pro-independence separatist activities.

The two foundations - Taiwan Foundation for Democracy and Taiwan Foreign Ministry's International Cooperation and Development Fund - will be banned from cooperating with any organisations, companies and individuals in the mainland, China's state news agency Xinhua on Wednesday cited Mr Ma Xiaoguang, spokesman of China's Taiwan Affairs Office, as saying.

China will punish any mainland organisations, companies and individuals that provide financial support to or serve the two foundations, Xinhua reported, adding that other measures will be adopted if necessary.

In addition, any deal or cooperation between four specific Taiwanese companies and mainland firms are not allowed due to their donations to the two foundations.

Executives at the four Taiwanese companies - solar producer Speedtech Energy, Hyweb Technology, medical equipment producer Skyla, and cold chain vehicle fleet management company SkyEyes - will be prohibited from entering mainland China.