Almost 30 percent of Taiwan's visitor arrivals in the first four months this year came from the mainland, making it the largest source area, according to data released by Taiwan authorities Tuesday.

A total of 1.75 million tourists visited the island from January to April, up 23.3 percent year on year and 525,000 were mainlanders.

With 352,000 tourists to the island in the first four months, Japan was Taiwan's second largest tourist source market. Tourists from Hong Kong and Macao amounted to 232,000 in the first four months.

The number of mainland tourists to Taiwan has increased rapidly since the island lifted a ban on mainland tourists in July 2008. The island attracted 606,000 mainland tourists in 2009.

Up to 25 mainland provinces and municipalities have gained travel access to the island, while residents in the other six will be allowed to tour Taiwan from July 18.

The mainland-based Cross-Strait Tourism Exchange Association expects more than a million mainland tourists to visit Taiwan in 2010.

More than 3 million Taiwanese travelled out of the island from January to April, up 16.2 percent year-on-year. About 763,000 visited Hong Kong while 709,000 visited the mainland.