China on Tuesday expressed strong protest against the Philippines over four of its vessels' "illegal intrusion" into the waters adjacent to China's Ren'ai Jiao.

The remarks were made by Chinese Foreign Ministry spokesperson Mao Ning at a regular press briefing.

Two Philippine transport vessels and two Philippine Coast Guard vessels on Tuesday trespassed into the waters adjacent to Ren'ai Jiao, part of China's Nansha Qundao in the South China Sea, to send construction materials to an illegally "grounded" military vessel on the island without the permission of the Chinese side, said Mao.

Video footage showed a Philippine Coast Guard vessel ignored China's repeated warnings and rammed into a Chinese Coast Guard vessel.

China Coast Guard spokesperson Gan Yu said that the Chinese Coast Guard strictly controlled and regulated the incident in a reasonable, legal, and professional manner.

Gan said, "The Philippines is dishonest in its statements, deliberately stirs up trouble, maliciously incites and sensationalizes, and continues to undermine peace and stability in the South China Sea region."

Mao also said the China Coast Guard took the necessary measures against the Philippine vessels in accordance with the law, and the on-site operation was professional, restrained, reasonable and lawful.

She noted that China and the Philippines have maintained communication on the proper management of the situation on Ren'ai Jiao for a long time, but the Philippine side once again reneged on its commitments to China, seriously infringing on China's territorial sovereignty and maritime rights and interests.

"We urge the Philippine side to cease its violations and provocations at sea and to refrain from taking any action that might complicate the maritime situation," the spokesperson said.

The China Coast Guard says it will resolutely safeguard the country's territorial sovereignty and maritime rights and interests.

(CGTN's reporter Cen Ziyuan contributed to the story.)

(Cover: A file photo of Chinese Foreign Ministry spokesperson Mao Ning. /Chinese Foreign Ministry)