China on Wednesday carried out a combat patrol to test "strike capabilities" near Scarborough Shoal in the South China Sea, a flashpoint area also claimed by the Philippines.
Beijing has continued to press its claims to almost the entire South China Sea despite an international tribunal ruling that its assertion has no legal basis.
On Wednesday, its People's Liberation Army's Southern Theater Command said it had "organised a joint combat patrol in the sea and air space near Huangyan Island", the Chinese name for the Scarborough Shoal.
The manoeuvres also tested the reconnaissance and early warning capabilities of its troops, Beijing said.
"All military activities that disrupt the South China Sea, create hotspots, and undermine regional peace and stability are all being controlled to the best extent," it added.
Scarborough Shoal is 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.
China in 2012 used coastguard vessels to take control of the shoal, a triangular chain of reefs and rocks that are part of a rich fishing ground and had long been used by Filipino fishermen as a safe harbour.
Also on Wednesday, the Philippines launched two days of joint sea and air exercises with the United States, Canada and Australia, according to a joint statement.
The manoeuvres will be held "within the Philippine Exclusive Economic Zone" and showcase "our collective commitment to strengthen regional and international cooperation in support of a free and open Indo-Pacific", top military officials of the four nations said.
- 'Aggravating tensions' -
Beijing and Manila have clashed in recent months following a series of confrontations in the South China Sea, including around a warship grounded for years by Manila on the contested Second Thomas Shoal.
In June, Chinese coast guard sailors brandished weapons including knives and an axe as they boarded Philippine naval vessels near the strategic reef.
The Philippine military said one of its sailors lost a thumb in the confrontation in which Beijing's coast guard also confiscated or destroyed Philippine equipment including guns.
Beijing blamed the escalation on Manila and maintains its actions to protect its claims are legal and proportional.
Last month, the United States said it would provide $500 million in additional military funding to the Philippines to combat Beijing's growing assertiveness.
Beijing said in response that "wooing countries from outside the region to provoke confrontation... will only undermine regional stability and aggravate tensions".
The investment "will only lead to greater insecurity" for Manila, it warned.
Philippines holds joint patrols
The Philippines launched on Wednesday two days of joint sea and air exercises with the United States, Canada and Australia, a joint statement said, as Beijing presses its territorial claim over the South China Sea.
The manoeuvres will be held "within the Philippine Exclusive Economic Zone" and showcase "our collective commitment to strengthen regional and international cooperation in support of a free and open Indo-Pacific", top military officials of the four nations said.
The exercises come as China's sabre-rattling towards Taiwan and over the South China Sea fuels fears of a potential conflict that could drag in the United States.
Beijing claims most of the strategic South China Sea, dismissing an international tribunal ruling that its claims were without basis.
Manila held separate naval exercises in the South China Sea last week, first with the United States and then with Japan two days later.
A joint coast guard exercise is also scheduled off Manila Bay on Friday between the Philippines and Vietnam.
The Philippines has a mutual defence treaty with the United States and signed a treaty with Japan last month that will allow the deployment of troops on each other's territory.
The "multilateral maritime cooperative activity" will be the first as a group by the four nations and involve naval and air force units, a Filipino military spokesman told AFP.
"The naval and air force units of participating nations will operate together enhancing cooperation and inter-operability between our armed forces," said the joint statement, which did not name the participating vessels and military units.
"Australia, Canada, the Philippines and the United States uphold the right to freedom of navigation and overflight, other lawful uses of the sea and international airspace, as well as respect for maritime rights under international law, as reflected in the UN Convention on the Law of the Sea."