This undated photo shows a view of Ren'ai Reef. (PHOTO / CHINA DAILY)

China Coast Guard issued warnings and "conducted necessary control" of four Filipino vessels that illegally entered waters near the Ren'ai Reef on Wednesday in accordance with the law, a spokesman said.

Gan Yu, spokesman for China Coast Guard, said in a statement on Wednesday night that without the approval of the Chinese government, two supply vessels and two vessels of the Philippines coast guard had illegally entered waters adjacent to the Ren'ai Reef of China's Nansha Islands.

The Chinese coast guard has closely monitored the movement of the ships and "effectively regulated" them in accordance with the law to prevent them from shipping illegal construction materials to the warship that is illegally stranded in the Ren'ai Reef, a spokesman said

The Chinese coast guard has closely monitored the movement of the ships and "effectively regulated" them in accordance with the law to prevent them from shipping illegal construction materials to the warship that is illegally stranded in the Ren'ai Reef, he said.

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Gu urged the Philippines to immediately stop its infringing activities in the waters, stressing that China has indisputable sovereignty over the Nansha Islands and their adjacent waters, including the Ren'ai Reef.

China Coast Guard will continuously carry out rights protection and law enforcement activities in the waters under China's jurisdiction in accordance with law, Gan added.

According to previous statements, the Chinese coast guard has handled the intrusion of vessels from the Philippines into waters near the Ren'ai Reef at least three times in August and September.

Earlier in August, Wu Qian, spokesperson of the Chinese Ministry of National Defense said that the China Coast Guard vessels had lawfully intercepted and taken warning enforcement measures against the Philippines' illegal transportation of construction supplies to China's Ren'ai Reef.

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Wu said that in the face of ineffective warnings through multiple verbal communications, water cannons were used as a means to avoid direct confrontation and collision.