TOKYO, Sept. 24 (Xinhua) -- Two Chinese surveillance vessels entered waters near the "Senkaku Islands" (Diaoyu Island and affiliated islets) early Monday morning, the Japan Coast Guard said.

The Japanese government has set up a countermeasures team at the prime minister's office following the arrival of the Haijian 66 and Haijian 46.

Relations between the two neighbors have soured in the aftermath of Japan's "purchase" and "nationalization plan" earlier this month of the Diaoyu Islands in the East China Sea, leading to mass anti-Japan protests in China and the cancellation of a series of ceremonial events in both countries to mark the 40th anniversary of the normalization of bilateral ties.