There was no sign Tuesday of the 1,000 fishing boats that Chinese media reported were heading toward the Senkaku Islands in the East China Sea, as the Japan Coast Guard meanwhile remained on high alert, warding off multiple Chinese government patrol ships in the waters near the disputed islets.

Meanwhile, in a tit-for-tat move against China’s aggressive response to the Japanese government’s recent nationalization of the islets, two Japanese nationals landed on Uotsuri but were warned off the islet by authorities.

“We will take every measure possible with a sense of urgency” to deal with the situation around the islets, Prime Minister Yoshihiko Noda told reporters in the morning.

The coast guard spotted a monitoring boat, the Yuzheng-35001 of the Chinese Agriculture Ministry’s Fisheries Bureau, within Japan’s contiguous zone about 24 nautical miles, or 44 km, from the islets at around 6:50 a.m.

The ship left the zone shortly before noon but re-entered the area later in the afternoon, the coast guard said.

Authorities later saw 10 more Chinese State Oceanic Administration surveillance ships enter the contiguous zone in the afternoon, Chief Cabinet Secretary Osamu Fujimura said.

The coast guard communicated with the ships, warning them not to enter Japanese waters, but those aboard the Chinese vessels argued that since the islets are a part of China their mission was justified.

Aside from the monitoring vessels, Fujimura said, no other Chinese ship had been sighted so far.

“As of right now, there is no definite information that a massive number of Chinese ships have entered our contiguous zone . . . but we will continue to work together among the related ministries to collect information and be on the alert,” he said.

The Japan Coast Guard said later in the evening that three of the Chinese government vessels briefly entered the territorial waters around 5:20 p.m., but the last one had exited around 6 p.m.

It also said they spotted another monitoring boat of the Chinese Agriculture Ministry’s Fisheries Bureau entering the contiguous zone later in the day, bringing the total number of Chinese government vessels that entered this zone to 12.

But this monitoring boat, as well as the 10 Chinese State Oceanic Administration surveillance ships, were out of the contiguous zone by around 8:20 p.m., the coast guard said, adding that the Yuzheng-35001 was the only Chinese vessel still in that zone as of 8:30 p.m.

Fujimura flatly denied media reports that the Defense Ministry was considering sending the Maritime Self-Defense Forces to bolster the security of Japanese waters in light of reports about the 1,000-ship Chinese fishing boat armada.

“This is not true. The police and the (coast guard) are fundamentally in charge of protecting the safety of Japanese waters,” Fujimura said. “But at the same time, there always needs to be a review of how we protect our territory, and I think it is meaningful for such discussions to take place.”

The Japan Times Ltd.