Beijing accused a Philippine ship of deliberately running into a Chinese coast guard vessel on Saturday near a flashpoint shoal in the South China Sea, the latest in a spate of similar incidents in recent weeks.

China claims almost all of the economically vital waterway despite competing claims from other countries and an international court ruling that its assertion has no legal basis.

A Chinese coast guard spokesperson said Saturday's incident took place off the disputed Sabina Shoal, which has emerged as a new hotspot in the long-running maritime confrontations between Manila and Beijing.

Shortly after noon (0400 GMT), a Philippine ship "deliberately collided with" a Chinese vessel near the shoal, known in Chinese as Xianbin, said spokesperson Liu Dejun, according to state broadcaster CCTV.

"China exercises indisputable sovereignty" in this zone, Liu added.

Liu condemned the Philippine vessel's "unprofessional and dangerous" conduct.

Sabina Shoal is located 140 kilometres (86 miles) west of the Philippine island of Palawan and about 1,200 kilometres from Hainan island, the nearest major Chinese landmass.

Philippine and Chinese vessels have collided at least twice this month near Sabina, which analysts say Beijing is seeking to further encroach upon, moving deeper into Manila's exclusive economic zone and normalising Chinese control of the area.

The discovery this year of piles of crushed coral at the shoal ignited suspicion in Manila that Beijing was planning to build another permanent base there, which would be its closest outpost to the Philippine archipelago.

Recent clashes between Philippine and Chinese vessels have also taken place around the Second Thomas Shoal.

A Filipino sailor lost a thumb in a clash there in June when Chinese coast guard members wielding knives, sticks and an axe foiled a Philippine Navy attempt to resupply a small garrison.

Sabina Shoal is also the rendezvous point for Philippine resupply missions to the garrison on Second Thomas Shoal.

The repeated confrontations prompted Manila to brand Beijing the "biggest disruptor" to peace in Southeast Asia at a defence conference this month.