Chinese sailors wielding knives, sticks and an axe foiled a Filipino attempt a week ago to resupply marines stationed on a derelict warship that was deliberately grounded atop the disputed shoal to assert Manila's territorial claims.

A Filipino soldier lost a finger in the clash, with Manila also accusing the Chinese coast guard of looting guns and damaging inflatable boats and other equipment.

"We are not downplaying the incident. It was an aggressive and illegal use of force," Defence Secretary Gilberto Teodoro told a news conference.

It was the latest and most serious incident in a series of escalating confrontations between Chinese and Philippine ships in recent months as Beijing steps up efforts to push its claims to nearly all of the strategically located waterway.

"We will not give up an inch, not even a millimetre of our territory to any foreign power," Teodoro said, restating President Ferdinand Marcos' South China Sea policy.

Teodoro said Manila will continue to resupply its warship at Second Thomas Shoal without asking for permission or consent from any other state.

Second Thomas Shoal lies about 200 kilometres (120 miles) from Philippine's Palawan island and more than 1,000 kilometres from China's nearest major landmass, Hainan island.

Beijing insisted its coast guard behaved in a "professional and restrained" way and blamed Manila for the clash.

In previous confrontations Chinese forces have used water cannon and military-grade lasers and collided with Filipino resupply vessels and their escorts.

"We see the latest incident in Ayungin (Second Thomas Shoal) not as a misunderstanding or an accident. It is a deliberate act of the Chinese officialdom to prevent us from completing our mission," Teodoro said.

Marcos, addressing the sailors who took part in the resupply mission, said Sunday the country "will not be intimidated or oppressed by anyone" but will "continue to exercise our freedoms and rights in support of our national interest, in accordance with international law".