TOKYO: Japan said Tuesday it expelled two Chinese coast guard ships from waters near disputed islands also claimed by Beijing.
The Chinese ships were approaching a Japanese fishing vessel operating in the area, Japan's coast guard said.
The two countries have a long-running territorial dispute over the Senkaku Islands -- known as the Diaoyu in China -- which lie between Taiwan and Japan's Okinawa.
They have figured for decades in bilateral tensions, which have worsened since Japanese Prime Minister Sanae Takaichi made comments about Taiwan in November that angered Beijing.
Chinese ships last entered waters Japan claims as its territory on June 10, but it is rare for vessels to approach Japanese fishing boats.
The coast guard "issued orders to leave... successfully forcing the Chinese coast guard vessels to leave Japanese territorial waters by approximately 9:20 am (0020 GMT) today," it said in a statement.
In addition, the coast guard "was deployed around the Japanese fishing vessel to ensure its safety".
There were four Chinese ships sailing around the area before two of them entered Japanese waters, the statement said.
It added that the activities of the Chinese coast guard vessels constituted "a violation of international law".
"The Japan coast guard will continue to respond calmly and resolutely in accordance with international and domestic law, and will take every possible measure to ensure the security of our territorial waters," it said.
China routinely deploys its coast guard ships around the disputed islands, prompting dangerous maritime standoffs with its Japanese counterpart.
China has also sent boats to other disputed waters in the East China Sea, which is believed to hold possible deposits of energy reserves, despite repeated protests by Japan to stop.
Takaichi said in November that Tokyo could intervene militarily in any attack on self-ruled Taiwan, which China views as its territory and has not ruled out taking by force.
Beijing condemned her comments, and has since urged its citizens against travelling to Japan as well as tightened trade restrictions on some Japanese firms.