Manila summoned Beijing’s envoy Monday after the China Coast Guard blocked and water cannoned Philippine vessels in the disputed South China Sea, President Ferdinand Marcos said.

The incident happened Saturday as the Philippine Coast Guard escorted charter boats carrying food, water, fuel and other supplies for Filipino military personnel stationed at Second Thomas Shoal in the Spratly Islands.

Beijing claims almost all of the South China Sea, through which trillions of dollars in trade passes annually, and has ignored a 2016 international court ruling that its assertion has no legal basis.

The Philippine military and coast guard have accused the China Coast Guard of breaking international law in blocking and firing water cannon at the re-supply mission, which prevented one of the charter boats reaching the shoal.

Another charter boat was successful in unloading its cargo.

China said it had taken “necessary controls” against Philippines boats that had “illegally” entered its waters.

“Our Secretary of Foreign Affairs summoned Ambassador Huang today and gave him a note verbale including pictures, video about what happened and we are awaiting their reply,” Marcos told reporters.

“The position of China, of course, is they say ‘this is ours so we are defending it’ and we, for our part, are saying ‘no, we own it so we are defending it’. So that becomes a grey area that we are discussing.”

The US State Department on Sunday condemned the Chinese actions, saying they were carried out by the coast guard and “maritime militia”, and that they directly threatened regional peace and stability.

Britain, Australia, Canada and the European Union also criticised Beijing’s actions.

Second Thomas Shoal is about 200 kilometres (124 miles) from the Philippine island of Palawan and more than 1,000 kilometres from China’s nearest major landmass of Hainan island.

China’s coast guard and navy vessels routinely block or shadow Philippine ships patrolling the contested waters, Manila says.