BEIJING: Beijing today accused the Philippines of "illegally" sending three aircraft into airspace over the disputed South China Sea, adding to longstanding territorial tensions between the two countries.

China claims almost the entire South China Sea and has brushed off competing claims by the Philippines and other countries, despite an international ruling that its assertion has no legal basis.

Beijing's People's Liberation Army (PLA) today said two Philippine C-208 and one N-22 aircraft "illegally ventured into the airspace around China's Nansha islands and reefs", also known as the Spratly Islands, a day earlier.

The Chinese armed forces "maintained control over the entire journey, warned and expelled" the aircraft, the statement by the PLA's Southern Theatre Command said.

The command released an audio clip it said showed a Chinese pilot warning one of the Philippine aircraft that it was "posing a security threat to Chinese islands and reefs", and ordering it to "leave immediately to avoid misjudgements".

The Philippine Coast Guard yesterday said Manila's fisheries bureau had flown two aircraft over the Spratly Islands to "assert the Philippines' sovereignty".

The planes "consistently challenged the illegal presence of Chinese maritime forces... (and) documented the unlawful activities conducted by the Chinese Coast Guard and Maritime Militia", the coast guard said.

Beijing and Manila have fought a war of words this week over the opposing side's conduct in the critical waterway, through which trillions of dollars of trade is estimated to pass each year.

On Tuesday, the Philippine Coast Guard said a Chinese navy helicopter flew as close as 3m of a surveillance flight carrying a group of journalists over the disputed Scarborough Shoal, condeming the "dangerous" manoeuvres.