Taiwan has accused China’s coast guard of triggering “panic”, after six Chinese officials briefly boarded a Taiwanese tourist boat.
They checked the ship’s route plan, certificate and crew licenses, and left half an hour later.
It comes less than a week after a Chinese fishing boat was pursued by Taiwan’s coast guard in the same area. The boat later capsized, killing two.
Beijing later said it would step up patrols in the Kinmen archipelago.
Kinmen lies just 3km(1.86 mi) away from China’s south-eastern coast, placing it on the frontline of tensions between China and Taiwan.
China sees self-ruled Taiwan as a breakaway province that will eventually, be part of the country, and has not ruled out the use of force to achieve this. But Taiwan sees itself as distinct from the Chinese mainland.
“We think it has harmed our people’s feelings and triggered people’s panic. That was also not in line with the interest of the people across the strait,” Kuan Bi-ling, head of Taiwan’s Ocean Affairs Council, said of the incident, which happened late afternoon on Monday.
The sightseeing vessel was carrying 11 crew members and 23 passengers, some of whom said they were nervous and worried they “would not be able to return to Taiwan”.
“I was quite shocked and very anxious,” said a female passenger in a video posted on China Times.
Ms Kuan said it was common for Chinese and Taiwanese tourist boats to enter the other side’s waters by accident, adding that: “Boats like these are not illegal at all.”
The military will not “actively intervene” in the incident to avoid escalating tensions, Taiwan’s Defence Minister Chiu Kuo-cheng told reporters in parliament on Tuesday.
“Let’s handle the matter peacefully,” he said.
Last week, two Chinese fishermen drowned while being chased by the Taiwanese coastguard off Kinmen.
Taipei said the fishing boat trespassed into Taiwanese waters and the four fishermen on board resisted an inspection. Their boat capsized when authorities gave chase.
Chinese state media said the families of the two survivors had arrived on Kinmen on Tuesday to bring them home.
Beijing “strongly condemned” the incident, saying it “seriously hurt the feelings of compatriots on both sides of the Taiwan Strait”.