The pursuit of oil, rising jobless rates and the need to cover up domestic public fury are behind Manila's recent territorial claims and its drive for oil drilling in the South China Sea, experts said.

Tensions have been flaring up between Beijing and Manila amid an impasse on China's Huangyan Island as the Philippine government laid a groundless claim over the island and sent a gunboat in early April to harass Chinese fishermen within China's territorial waters off the island.

Media in Manila on Tuesday questioned attempts by some Philippine companies to speed up the joint development of oil and gas in the South China Sea, claiming that the so-called "sovereignty" issue is more important than business interests.