The Chinese boat was carrying four people when it capsized near the Kinmen Islands, throwing all onboard into the water, Chinese and Taiwanese authorities said.
“The malignant incident severely harmed the feelings of compatriots on both sides of the Taiwan Straits,” Zhu Fenglian, a spokesperson for China’s Taiwan Affairs Office, said in a statement.
Beijing has urged the Taiwanese authorities to immediately investigate the incident, Zhu added.
Taiwan’s Coast Guard Administration said in a statement they had discovered an unnamed mainland speedboat on Wednesday afternoon near Kinmen islands that was “0.86 miles nautical miles within prohibited waters”.
Kinmen is administered by Taiwan, but its nearest point is just under five kilometers from China’s Xiamen.
“During our law enforcement process, the mainland boat accidentally capsized and four mainland crew members fell into the sea,” the coast guard said in a statement, adding that search-and-rescue operations were immediately launched.
Two crew members were rescued while two others were found unconscious.
“They were sent to hospital for emergency treatment which was ineffective,” the statement said.
The authorities will notify the families of the deceased crew members “through channels”, while the two rescued crew have been brought to Kinmen for investigation, it added.
China claims democratic Taiwan as part of its territory and has never renounced the use of force to bring the self-ruled island under its control.
The incident comes against a backdrop of high tensions across the Taiwan Strait.
Taiwan’s presidential election, held in January, was won by the ruling Democratic Progressive Party’s Lai Ching-te, who Beijing regards as a “separatist”.
Chinese President Xi Jinping has ramped up rhetoric in recent years for the “unification” of Taiwan with China.
