China Demands Japan Release Activists Arrested on Gas-rich Disputed Islands

China has urged Japan to immediately and unconditionally release 14 activists who planted the Chinese flag on a disputed island that has long been a source of tension between the two Asian powers.

Fourteen activists from China, Hong Kong and Macau travelled by boat to the group of islands, called Senkaku in Japanese and Diaoyu in China, on the emotionally charged anniversary of Japan's surrender at the end of the second world war. Five were arrested on the islands, and nine others detained on their boat, Japan's coastguard said earlier.

In discussions with Japanese officials, Chinese vice-foreign minister, Fu Ying, demanded that Japan ensure the safety of the 14 Chinese nationals and immediately and unconditionally release them, the Chinese foreign ministry said on its website.

Fu also "made solemn representations on Japan's unlawful detention of Chinese nationals on the Diaoyu Islands", the ministry website said.

Japan protested to China's ambassador over the activists' landing and the prime minister, Yoshihiko Noda, said Tokyo would deal with the matter strictly in accordance with the law.

China's Xinhua state news agency said Japan had pushed tension "to a new high".

"The tensions are fully due to irresponsible clamouring and attempts by some Japanese politicians and activists to claim the islands, which ... indisputably belong to China," it said.

Friction over the uninhabited isles, which are near potentially rich gas deposits, had already been heating up.

Several of the activists jumped into the sea, swam and waded ashore. The group said its boat had been rammed by the coastguard and hit with water cannon. A Japanese official denied that any serious damage had been done to the boat.

Chinese media published photographs of the activists planting the country's flag on a rocky shore. "We've waited 10 years for this. We finally managed to get ashore," the captain of the protest ship was quoted as saying on Hong Kong television.

A separate row over rival claims by South Korea and Japan to other rocky islands has also intensified, signalling how the region has failed to resolve differences nearly seven decades after Japan's defeat at the end of the second world war.

The friction in part reflects scepticism over the sincerity of Japan's apologies for wartime and colonial excesses.

On Tuesday, South Korea's Lee Myung-bak told a group of teachers that Emperor Akihito should apologise sincerely if he wanted to visit South Korea, saying a repeat of his 1990 expression of "deepest regrets" would not suffice.

Japan, noting that it had never broached the idea of a visit by the emperor to South Korea, lodged a protest with Seoul over the remarks. Akihito has spent much of the past two decades trying to heal the wounds of a war waged in his father's name.

Lee, whose visit on Friday to the island claimed by South Korea and Japan frayed ties between the two US allies, called Japan an "important partner that we should work with to open the future".

But in remarks commemorating Korea's liberation from Japan's colonial rule between 1910 and 1945, he also said the countries' tangled history was "hampering the common march toward a better tomorrow.

He urged Japan to do more to resolve a dispute over compensation for Korean women abducted to serve as sex slaves for wartime Japanese soldiers, known by the euphemism "comfort women" in Japan and long a source of friction.

"It was a breach of women's rights committed during wartime as well as a violation of universal human rights and historic justice. We urge the Japanese government to take responsible measures in this regard," Lee said.

Japan says the matter was closed under a 1965 treaty establishing diplomatic ties. In 1993, Tokyo issued a statement in the name of its then-chief cabinet secretary apologising to the women and two years later set up a fund to make payments to the women, but South Korea say those moves were not official and so not enough.

Speaking at a ceremony marking the war's end in Japan on Wednesday, Noda acknowledged the "enormous damage and suffering" caused by Japan to other countries, especially in Asia.

"We deeply reflect upon [that] and express our deepest condolences to the victims and their families," he said, vowing that Japan would never go to war again.