Chinese coast guard vessels, air patrols and fishing fleets have re-asserted their disputed maritime claims in two distant areas Saturday, despite last month's ruling by an international tribunal that their territorial claims in the South China Sea have no legal basis.
Japan filed a protest against China Saturday after saying it saw at least six Chinese coast guard vessels and more than 200 fishing boats near Japanese-controlled Senkaku Islands. China also claims these islands, which it calls the Diaoyu.
Chinese vessels are allowed to operate in the region, but the large number seen Saturday raised alarm.
Japan's Foreign Ministry demanded that the ships leave the area, stating that three of the coast guard vessels were armed with what appeared to be gun batteries.
Beijing responded by reiterating its position that the islands are "China's inherent territory."
On the same day, China announced that it has conducted a combat air patrol over the disputed South China Sea to improve its fighting ability.
The Air Force did not specify when the exercises took place, but state news agency Xinhua reported that several types of planes including bombers and fighters took off from multiple airports.
Last month, a United Nations-backed court in The Hague ruled that China had no claim to disputed part of the South China Sea.
China has asserted territorial claims in large swaths of the South China Sea in recent years, transforming reefs into artificial islands that can support military installations and airstrips, ignoring competing claims in the region by Brunei, Malaysia, Vietnam and Taiwan, as well as the Philippines.
The Permanent Court of Arbitration ruled that Beijing's territorial claims in the region have "no legal basis."
An estimated $5 trillion in global trade passes each year through the South China Sea, which is home to rich fishing grounds and a potentially vast wealth of oil, gas and other natural resources.