Japan coastguard says more China ships in disputed waters

Japan said three Chinese surveillance ships entered its territorial waters off disputed East China Sea islands on Sunday, hours after one of Beijing's fisheries patrol boats sailed into the zone.

The three marine surveillance ships entered the 12-nautical-mile territorial zone off Uotsuri, one of the Senkaku islands, shortly before 1:00 pm (0400 GMT), the Japan Coast Guard said in a statement.

It said the ships left the zone after about three hours.

The incident came hours after Japan said a Chinese fisheries patrol boat briefly entered territorial waters off another disputed island on Sunday.

Beijing claims the Japanese-controlled islands, which it calls the Diaoyus.

The incidents were the latest in a series since Tokyo nationalised three islands in the chain in September, in what it said was merely an administrative change of ownership. The action sparked fierce protests in China.

The same Chinese fisheries patrol ship briefly entered the territorial zone on Saturday, as Japan's leader vowed he would not tolerate challenges to his country's ownership of the islands.

Prime Minister Shinzo Abe, making his first visit to the United States since he took office in late December, said Japan "simply cannot tolerate any challenge now and in the future" to its ownership.

"No nation should make any miscalculation or underestimate the firmness of our resolve," Abe said Friday in Washington.

But speaking after White House talks with President Barack Obama, Abe also said he has "absolutely no intention to climb up the escalation ladder".