Taiwan must "bear the consequences" of its Coast Guard using a water cannon against a Chinese fishing boat near an atoll in the South China Sea, a Chinese government spokesperson said on Wednesday.
A Taiwan Coast Guard ship this month fired its water cannon, saying the boat failed to respond to warnings to move away from restricted waters close to the Taiwan-controlled Pratas Islands.
The ship then suffered engine failure and was towed away by a nearby Chinese vessel, Taiwan's Coast Guard said.
Chen Binhua, a spokesperson for China's Taiwan Affairs Office in Beijing, said China has "indisputable sovereignty" over the Pratas and surrounding waters.
"Mainland vessels operating in the relevant waters are entirely legal and justified. We will resolutely safeguard the lives and property of our people," Chen said.
Taiwan's "treatment of mainland vessels roughly in a dangerous manner that endangers the lives and property of the personnel involved is maliciously stirring up cross-strait confrontation and they must bear all consequences arising from this," Chen said, without elaborating on the consequences.
A Taiwan official with direct knowledge of the situation around the Pratas told Reuters that the Coast Guard carried out "normal law enforcement" during the incident and responded in a "very careful and proportionate way".
The Pratas Islands lie roughly between southern Taiwan and Hong Kong. Security experts see them as vulnerable to Chinese attack due to their distance — more than 400 km (250 miles) — from Taiwan.
China claims democratically governed Taiwan as its own territory and has increased its military presence around the island over the past five years. The government in Taipei rejects China's claim.
China recognises no claims of sovereignty by Taiwan, including over the Pratas Islands, and Chinese coast guard ships have increased patrols.
'Grey Zone' Activities
Taiwan says China is increasing its "grey zone" tactics that stop short of outright military action to pressure Taiwan.
Speaking at a forum in Taipei, Lii Wen, deputy secretary-general of Taiwan's National Security Council, said China was using a wider range of ships in its "incremental acts of aggression," including militia boats and research vessels.
"Grey zone activities under the threshold of conflict have raised serious concerns for their potential to disrupt transportation or damage critical infrastructure," he added.
Taiwan's Coast Guard is in charge of day-to-day security for Pratas rather than the military.
The Pratas Islands are a national park. They have an airstrip but no permanent civilian population.