HANOI, Vietnam — Two Chinese aircraft landed on disputed reefs and Beijing’s coast guard reportedly blocked a Filipino boat from a contested shoal, in acts of defiance after a landmark ruling found China’s vast claims in the South China Sea legally baseless.

Vietnam protested Thursday that the recent Chinese actions seriously violated Vietnamese sovereignty.

Chinese state media reported that two Chinese civilian aircraft landed successfully Wednesday on two new airstrips on Mischief and Subi reefs. China also said it had completed four lighthouses on disputed reefs and was launching a fifth.

In the Philippines, ABS-CBN TV network reported that Chinese coast guard ships blocked a Filipino fishing boat from approaching the disputed Scarborough Shoal on Thursday. Journalist Chiara Zambrano reported the two speedboats approached and encircled the Filipino boat carrying her and local fishermen.

One video the network aired showed the Filipino boat being tailed by a white Chinese coast guard ship in an area Zambrano said was a few miles (kilometers) from Scarborough, where the local fishermen were blocked from entering to fish. Another video showed the Chinese coast guard personnel using a bullhorn and ordering the Filipinos to leave “this area immediately.”

Mayor Arsenia Lim of the northwestern town of Masinloc, where the fishermen live, said they sailed to Scarborough to test China’s compliance with the ruling.

“What they’re doing is bad because it shows as if there is no law,” Lim told The Associated Press by telephone. “Our government should defend the livelihood of these people because it’s the only place where they get their income.”

The ruling Tuesday from the Permanent Court of Arbitration in The Hague, Netherlands, was based on the 1982 U.N. Convention on the Law of the Seas, which both China and the Philippines ratified. The Philippines sought arbitration in 2013 after witnessing China’s activities in Scarborough and elsewhere in the sea rich with fish and potential energy resources.

Beijing boycotted the case entirely and declared the ruling null and void. The tribunal has no power of enforcement, making the ruling’s impact uncertain.