The Philippines celebrated Independence Day on Thursday by raising national flags in military bases across the country and on nine islands it has illegally occupied in the South China Sea, a "severe" move that experts say will further harm the feelings of the Chinese people.

The flag-raising ceremony took place at 7 am in all the detachments on nine islands and reefs of the Nansha Islands, including China's Ren'ai Reef, according to navy spokesman Lieutenant Commander Gregory Fabic, quoted by the Manila-based Inquirer Wednesday.

While the ceremony is held every year, this year it comes as relations between China and the Philippines are strained by territorial disputes.

Manila held the flag-raising ceremonies to draw international attention to its claims to the Nansha Islands and in the meantime to discomfort China, said Wu Shicun, president of the National Institute for the South China Sea.

But raising even more flags on Independence Day will not change the fact that it has illegally occupied Chinese territory, Wu said.

The Philippines has submitted the territorial dispute to the UN International Tribunal for the Law of the Sea for arbitration. In response, China's foreign ministry reaffirmed China would not accept nor participate in the arbitration.