“[The Chinese coastguard] warned them in both Chinese and English, and reiterated China’s indisputable sovereignty over Nansha Qundao, or Nansha Islands, including Xianbin Jiao, and their adjacent waters,” the report said.

The incident came on the eve of a new regulation authorising the Chinese coastguard to detain foreign nationals for up to 60 days if they trespass in the South China Sea, which China considers its territorial waters. Maritime observers expect Beijing to show restraint when it comes to implementing the guidelines.

01:55

Beijing denies Manila’s claim that Chinese ships making ‘artificial island’ in South China Sea

Beijing denies Manila’s claim that Chinese ships making ‘artificial island’ in South China Sea

Chinese defence ministry spokesman Zhang Xiaogang said it was “legitimate and reasonable” for China to enforce laws in the Spratly Islands, including the Sabina Shoal and the Second Thomas Shoal, or Renai Jiao, which were “waters under Chinese jurisdiction” and China’s “inherent territory”.

Zhang added that Manila had “broken promises”, “played with fire” and escalated tensions.

“It cooked up and spread disinformation about Xianbin Reef in an attempt to cover up its infringements and provocations,” Zhang said, referring to Manila’s claim that Beijing was crushing coral reefs to create an “artificial island” at an unoccupied reef 75 nautical miles from Palawan island in the western Philippines.

In May, the Philippine coastguard stated that “only China” was to blame for the crushed reefs, and vowed to bolster its presence at shoals and islets in the South China Sea.

Manila also claimed that Beijing sent a hovercraft and an aircraft to conduct exercises in the waters, resulting in the deployment of lead Philippine patrol ship BRP Teresa Magbanua to monitor alleged “illegal activities”.

“Such behaviour is like a thief crying ‘stop thief’ and fully shows that the Philippine side is undoubtedly the one undermining peace and creating instability,” Zhang said, adding that the Chinese military would continue to take all necessary countermeasures against Manila’s “dangerous” and “escalatory” moves.

China’s new rule for arrest was met with strong protest from Manilla. Defying Beijing’s warnings, the Philippine military chief on Thursday urged fishing crews to keep operating in the country’s exclusive economic zone in the South China Sea.

“That’s our message to our fishermen, for them not to be afraid but to just go ahead with their normal activities in our exclusive economic zone,” Philippine armed forces chief Romeo Brawner said on Friday. “We have the right to exploit the resources in the area, so our fishermen have no reason to be afraid.”

Criticising China’s actions in the waters as baseless, opposition and fishing industry groups protested outside Beijing’s consulate in Manila on Friday.

“Fishermen and the Filipino people will defy the order. It is China which should be held accountable as trespassers,” said Mong Palatino, secretary general of opposition party-list group Bayan Muna.