Tourists from the Chinese mainland visit the Sun-Moon Lake in southeast China's Taiwan Province March 18, 2009. Groups of over 10,000 mainland tourists organized by Gangzhong Lu International Travel Agency are in their trips to Taipei, Keelung, Hualien and the Sun-Moon Lake in succession.

Taiwan police have said they don't think a mainland tour group was the target of an airgun attack that damaged two yachts on Sun Moon Lake on Wednesday, China News Service reported yesterday.

The wind shields of two yachts, including the President One, which once served Chiang Kai-shek, were shot by an airgun several times.

The President One had its right front windshield broken by one pellet, while the other boat, Minghong, had each of its two windshields broken, police said.

Officers have picked up airgun pellets at the scene and confirmed the vandalism took place either on Tuesday night or on early Wednesday.

Police also discovered several streetlights in a park next to the wharf had been damaged with airgun pellets.

The attack came before a visit to the lake by 1,600 mainlanders. The President One was not one of the 20 yachts chartered for the group and had never served mainland tourists before, police have excluded any links between the sabotage and mainland tour group's visit.

The captain of the President One found his yacht had been damaged at about 9am on Wednesday, according to Southeast Express.

The mainland tour group encountered protests from a local woman when they were having their first lunch on the island.