A group of Filipino protesters has landed on a disputed Philippine-held island in the South China Sea, a local government official said on Sunday, in a risky expedition that may trigger a strong reaction from China.

About 50 protesters, most of them students, reached Pagasa island in the Spratly archipelago on Saturday in a stand against what they say is Beijing's creeping invasion of the Philippine exclusive economic zone, said Eugenio Bito-onon, the island's mayor.

"The 'freedom voyage' arrived at about 8:30 a.m. on Saturday from Balabac island on a motor launch," Bito-onon said, adding the protesters left southern Palawan on Thursday in fine weather to make the long sea crossing.