BEIJING: Tokyo branded as “very dangerous” a move by Beijing Saturday to set up an “air defense identification zone” over an area that includes disputed islands controlled by Japan, but claimed by China.

In a move that raised the temperature of a bitter territorial row between the two countries, China’s Defense Ministry said that it was setting up the zone to “guard against potential air threats.”

It later scrambled air force jets, including fighter planes, to carry out a patrol mission Saturday in the newly established zone.

The outline of the zone, which is shown on the Chinese Defense Ministry website and a state media Twitter account, covers a wide area of the East China Sea between South Korea and Taiwan that includes airspace above the Tokyo-controlled islands known as the Senkaku to Japan and Diaoyu to China.

Junichi Ihara, who heads the Japanese Foreign Ministry’s Asian and Oceanian affairs bureau, lodged a protest by phone to Han Zhiqiang, minister at the Chinese Embassy in Japan, the ministry said in a statement.

He said Japan could “never accept the zone set up by China” as it includes the Tokyo-controlled islands, the statement said.

Ihara also told the Chinese side that such move by Beijing would “escalate” current bilateral tensions over the islands, branding it “very dangerous.”

Japan’s Vice Foreign Minister Akitaka Saiki plans to summon the Chinese ambassador to Japan, Cheng Yonghua, as early as possible on Monday and state Japan’s position on the matter, Kyodo news agency reported.

Chinese Defense Ministry spokesman Yang Yujun said the establishment of the zone, which became operational on Saturday morning, was aimed at “safeguarding state sovereignty, territorial land and air security, and maintaining flight order.”

Along with the creation of the zone in the East China Sea, the Defense Ministry released a set of aircraft identification rules that must be followed by all planes entering the area, under penalty of intervention by the military.

Aircraft are expected to provide their flight plan, clearly mark their nationality, and maintain two-way radio communication allowing them to “respond in a timely and accurate manner to the identification inquiries” from Chinese authorities.

Shen Jinke, spokesman for the People’s Liberation Army Air Force, said late Saturday that it had conducted a patrol of the area using early warning aircraft and fighters.