This story has been updated from an earlier version.

The Philippines Coast Guard confirmed on Friday that its officers killed a Taiwanese fisherman when its sailors fired on two fishing boats that had entered waters claimed by the Philippines on Thursday.

Taiwan had demanded an apology from the Philippines on Friday, the Wall St. Journal reported, and it insisted the Philippines launch an inquiry about the fatal shooting in the disputed South China Sea.

Taiwan Foreign Minister David Lin had blamed the Philippines Coast Guard for opening fire on the Taiwanese boat, the Kuang Ta Hsing No. 28, which belonged to a vessel that's part of the fisheries division of the Philippine Department of Agriculture, early on Thursday. He said the incident occurred in waters 170 miles (315 km) south of Taiwan, the Associated Press reported.

“We strongly condemn the fatal shooting of a Taiwanese fisherman by the Philippines fishery department,” Lin told reporters. “We urge the Philippines government to open a full investigation on this case and send their apology to Taiwan's government.”

The Philippines naval commander in the area said all Philippine ships were in the port or very close to the Philippines coast at the time, the the AFP reported.

“The Philippines Navy denies any involvement in ... an incident where a Taiwanese fisherman was reportedly shot and the wound led to his death,” the Philippines Navy said in a statement.

However, the Philippines Coast Guard, which is a separate service from the Navy, had not commented on the matter yet.

“We cannot confirm [the report of shooting]," Philippines Foreign Secretary Albert del Rosario told the A.P. earlier on Friday. "We will check that.”

The South China Sea has long been a bone of contention among several South East Asian nations. Overlapping territorial claims by China, the Philippines, Vietnam, Taiwan, Malaysia and Brunei have led to tensions in recent months.

Taiwan has been independent since 1950, but China regards it as a rebel region that must be reunited with the mainland.