China's Ministry of National Defense urged the Philippines on Sunday to stop all infringements and provocative actions around Ren'ai Reef in the South China Sea.

Ministry spokesman Senior Colonel Wu Qian made the remarks after Philippine ships illegally entered waters adjacent to Ren'ai Reef, off China's Nansha islands.

Wu said on Saturday, three Philippine vessels illegally intruded into the waters during an attempt to transport supplies and construction materials to a military vessel that the Philippines intentionally grounded on the reef in 1999.

The China Coast Guard lawfully and properly regulated, intercepted and expelled the Philippine vessels, resolutely thwarting the Philippines' provocative attempt to encroach on Chinese territory, Wu said, adding that the incident was entirely provoked by the Philippines, and China's handling of the situation was standard, reasonable, lawful and professional.

China Coast Guard spokesman Gan Yu said in a statement issued on Saturday that just 18 days after the last round of resupply — which he earlier described as "a temporary special arrangement out of humanitarian concern" — the Philippines had broken its pledge to respect China's territorial waters and again dispatched two coast guard ships and one supply vessel to infringe into the waters near Ren'ai Reef, attempting to carry out "abnormal resupply operations and transport construction materials" to the grounded vessel.

He said the Philippine side had provocatively seized the opportunity to infringe on China's rights and intentionally destroy the peace and stability of the South China Sea.

"At the scene, the Philippine supply ship disregarded the Chinese side's repeated dissuasion, warnings and navigation control, and still forcefully intruded," Gan said.

He said that in response, the China Coast Guard implemented interception, obstruction and expulsion following laws and regulations, handling the situation in a "reasonable, lawful, professional and standardized manner".

"We warn the Philippine side: those who play with fire will only humiliate themselves," he said. "The China Coast Guard is always on high alert, resolutely safeguarding national territorial sovereignty and maritime rights and interests."

Wu emphasized that China holds indisputable sovereignty over the Nansha islands, including Ren'ai Reef and adjacent waters.

"China's sovereignty and territorial integrity are not to be violated," he said.

He said China is willing to properly resolve disputes with the Philippines through dialogue and negotiation. However, the Philippines, acting in bad faith, had attempted to illegally send construction materials to the grounded vessel on Ren'ai Reef to turn it into a permanent facility. China would not sit idly by when such action was taken, Wu said.

"We warn the Philippines to cease making any statements that may escalate tensions and stop all acts of encroachment," he said. "If the Philippines continues to challenge China's bottom line, China will continue to take resolute measures to firmly defend its territorial sovereignty and maritime rights and interests."