China claims almost the entire South China Sea, brushing off rival claims from other countries -- including the Philippines -- and an international ruling that its assertion has no legal basis.

Vessels from the two sides have clashed frequently in the past year, resulting in injuries and damages.

Tensions flared again on Wednesday, with Manila releasing a video appearing to show a Chinese coast guard ship firing a torrent of water at the Philippines fisheries department vessel BRP Datu Pagbuaya.

Other footage apparently taken from the Philippine ship showed its crew shouting "Collision! Collision!" as the much larger Chinese vessel approaches its right-hand side before crashing into it.

The water cannon was aimed "directly at the vessel's navigational antennas", the Philippine coast guard and fisheries ministry said in a joint statement.

The Chinese vessel "intentionally sideswiped" the ship before launching a second water cannon attack, the statement said.

China's coast guard said in an initial statement that Philippine ships "came dangerously close" and that its crew's actions had been "in accordance with the law".

But in a later statement, it accused Manila of making "bogus accusations in an attempt to mislead international understanding".

It said the Philippine ship had "turned at a great angle and reversed, deliberately colliding" with the Chinese ship.

Video released by Manila said to be drone footage of the collision does not show the Philippine ship reversing.

AFP has not independently verified the videos.

- Growing tensions -

Scarborough Shoal -- a triangular chain of reefs and rocks -- has been a flashpoint between the countries since China seized it from the Philippines in 2012.

Since then, Beijing has deployed patrol boats that Manila says harass Philippine vessels and prevent Filipino fishermen from accessing a fish-rich lagoon there.

The shoal lies 240 kilometres (150 miles) west of the Philippines' main island of Luzon and nearly 900 kilometres from the nearest major Chinese land mass of Hainan.

Tensions between Manila and Beijing in the South China Sea escalated last month when Philippine President Ferdinand Marcos signed two laws defining the country's sea waters and imposing fixed lanes for foreign ships, prompting China to summon the Philippine ambassador.

And ties frayed further when the Philippines and the United States signed a security deal allowing both sides to share classified information.

In a separate incident, Beijing said Monday it had taken "control measures" against Philippine ships it accused of "illegally gathering" near Iroquois Reef in the disputed Spratly Islands.

On that occasion, Beijing warned Manila to "immediately stop its infringements and provocations".

Manila said a Chinese navy helicopter had "harassed" Philippine fishing vessels in the area, and shared video footage that purported to show the aircraft hovering low over a Philippine boat.

The Philippine coast guard said it had deployed two vessels in the area "to ensure the safety and security of Filipino fishermen exercising their right to fish freely" there.

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