Tokyo: Japanese Prime Minister Shinzo Abe should stay away from a controversial Tokyo war shrine, an international think tank said Thursday, as it offered ideas on defusing mounting Sino-Japanese tensions.

In a new report, the International Crisis Group (ICG) warned that Abe`s visit to the Yasukuni shrine last December "triggered a bitter argument as to whether Japan has fully atoned for its Second World War aggression, a still vivid sore in the region".

The Brussels-based group also chided China for asserting greater authority over regional airspace, a move that it said "deepened Tokyo`s anxiety that Beijing desires both territory and to alter the regional order".

"China should calm anti-Japan rhetoric, delink wartime history from the islands dispute and open senior political channels to Japan," said the group`s China analyst, Yanmei Xie, referring to a territorial dispute between both countries in the East China Sea.

"Japan should avoid actions and comments suggesting revisionist history views," Xie added.

The 51-page report comes as Sino-Japanese relations have reached their lowest point in years and as both countries face the increased risk of a military clash.

It also comes weeks ahead of the August 15 anniversary of Japan`s World War II defeat, a date many politicians in Tokyo mark by visiting Yasukuni, where 14 top indicted war criminals are enshrined, as well as Japan`s dead from World War II and other conflicts.

China and South Korea see the shrine as a symbol of what they say is Tokyo`s unwillingness to repent for its aggressive warring last century. The US tries to discourage visits, which it views as unnecessary provocation.

Abe, who drew condemnation from Seoul and Beijing with his December 26 trip to the shrine, has not indicated whether he plans to make a return visit next month. The conservative prime minister stayed away during a visit by nearly 150 Japanese lawmakers in April.

In its report, ICG warned that both countries should "refrain from escalatory actions" near a group of long-disputed East China Sea islands, called Diaoyu by Beijing and Senkaku by Japan.

"China should refrain from chasing Japanese fishing vessels and send no aircraft, including drones, into the airspace above or near the islands," it said, adding that there had been "repeated close calls" as a result of Beijing`s willingness to "take risks to keep foreign vessels and aircraft away from its fleets".

"Leadership in both countries needs to set a tone that prioritises diplomacy to calm the troubled waters," it said.