The Philippine vessels’ actions “seriously endangered the safety of Chinese vessels and personnel”, ministry spokesman Jiang Bin.

Jiang neither confirmed nor denied that there had been a collision involving two Chinese vessels on Monday.

“We demand that the Philippine side immediately stop its infringing and provocative rhetoric and actions,” Jiang said.

“China reserves the right to take necessary counter-measures.”

The Scarborough Shoal has been a major source of tension in what is a strategic conduit for more than US$3 trillion of annual ship-borne commerce.

Footage from the Philippine coast guard (PCG) showed a Chinese coast guard ship trailing the PCG vessel before a Chinese navy ship suddenly cut across the path of the other Chinese ship, colliding with it and damaging the forecastle of the coast guard vessel.

It was the first known crash between Chinese vessels in the area.

The Philippines today said it bore no responsibility for the collision.

“It was an unfortunate outcome, but not one caused by our actions,” Manila’s foreign minister Theresa Lazaro said in a statement.

The Philippine coast guard deployed three vessels on Monday to deliver supplies for Filipino fishermen in the Scarborough Shoal before the collision took place, Manila said on Tuesday.

The confrontation was the latest in a series of incidents amid a period of heightened tensions between Manila and Beijing over territorial disputes in the South China Sea.

A 2016 ruling of an international arbitral tribunal voided Beijing’s sweeping claims in the region, saying they had no basis under international law, a decision China rejects.