The Japan Coast Guard this year issued exclusion orders to a total of 80 Chinese fishing vessels suspected of illegally operating in Japanese territorial waters in the East China Sea, a source familiar with the matter said Thursday.

Japan has told China that foreign fishing ships are not allowed to operate "without permission" in the waters around the Senkaku Islands, controlled by Tokyo but claimed by Beijing, the source said.

File photo taken in September 2012 shows the Senkaku Islands in the East China Sea. (Kyodo)

The uninhabited islets, called Diaoyu in China, have long been at the center of conflict between the Asian countries, as Beijing has ratcheted up pressure on Tokyo by constantly sending its vessels into or near the Japanese territorial waters to challenge the status quo.

A Chinese-set suspension of fishing in the East China Sea is scheduled to end Monday, sparking concern that Beijing may send an inordinate number of government and fishing ships into or near the Senkaku Islands.

In August 2016, a group of China Coast Guard vessels and as many as 300 fishing boats crowded around the islets. Some of them repeatedly intruded into Japanese waters despite a flurry of high-level protests from Tokyo.

The coast guard's exclusion orders target foreign fishing ships engaging in illegal operations or trying to do so in Japan's territorial waters, the source said, adding its patrol boats urge them to move out by using radio or an electric bulletin board.

All the orders this year were issued for four months through April, the source said. The Japan Coast Guard warned 138 Chinese fishing vessels in 2020, 147 in 2019, 76 in 2018 and 10 in 2017.

In February, meanwhile, China enforced a controversial law enabling its coast guard to use weapons when foreign ships involved in illegal activities in waters it claims do not obey orders, making Sino-Japanese relations more fragile over maritime security.

Chinese Foreign Minister Wang Yi has recently justified the nation's sending of official ships to the area, saying "unknown Japanese fishing vessels" entered the waters of the islands.

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