The Philippines and China exchanged accusations of intentionally ramming coast guard vessels in disputed waters of the South China Sea on Saturday, the latest in an escalating series of clashes in the vital waterway.

The collision near the Sabina Shoal was their fifth maritime confrontation in a month in a longstanding rivalry.

Beijing claims almost the entire South China Sea, including parts claimed by the Philippines, Brunei, Malaysia, Taiwan and Vietnam. Portions of the waterway, where $3 trillion worth of trade passes annually, are believed to be rich in oil and natural gas deposits, as well as fish stocks.

The Permanent Court of Arbitration in 2016 found China's sweeping claims had no legal basis, a ruling Beijing rejects.

Philippine Coast Guard spokesperson Jay Tarriela showed videos of Saturday's confrontation at a press conference, saying China Coast Guard vessel 5205 "directly and intentionally rammed the Philippine vessel" without provocation.

The ramming damaged the 97-metre (320-foot) Teresa Magbanua, one of the Philippines' largest coast guard cutters, but no personnel were injured, Tarriela said.

Liu Dejun, a spokesperson for China's coast guard, said in a statement a Philippine ship, "illegally stranded" at the shoal, had lifted anchor and "deliberately rammed" a Chinese vessel. He called on the Philippines to withdraw immediately or bear the consequences.