|Japan's arrest of a Chinese fishing boat captain earlier this month sent ties with its neighbour into a tailspin [AFP]
Japan has released a Chinese fishing boat captain whose arrest two weeks ago sparked the worst row between the nations in years, Japanese media reports say.
Prosecutors earlier on Friday cited the damage already done to relations with Beijing as a factor behind their decision to free Zhan Qixiong.
The Chinese captain was due to fly directly back to China via charter jet after being set free in the small town of Ishigaki, where he was being held.
Japanese authorities detained Zhan after his trawler collided with two Japanese coast guard vessels near a string of contested islands in the East China sea on September 8.
The uninhabited islands, known as Diaoyu in China and as Senkaku in Japan, lie in an area with rich fishing grounds. The area is believed to have sizable oil and gas deposits. The islands are also claimed by Taiwan.
Fourteen crew members and the boat were returned earlier.
Japan's decision to free the Chinese skipper follows China's arrest of four Japanese nationals for allegedly filming a military facility in Hebei province.
China's state-run Xinhua news agency said earlier that the four men are being investigated for entering a military zone without authorisation and illegally videotaping military targets.
Fujita Corp, a Tokyo-based construction and urban redevelopment company, identified the four men - Yoshiro Sasaki, 44, Hiroshi Hashimoto, 39, Sadamu Takahashi, 57 and Junichi Iguchi, 59 - as employees.
Tatsuro Tsuchiya, a Fujita spokesman, said the company has not been able to contact the men since receiving a one-word text message from one of them on Tuesday morning that read "Help".
"Even though damage has already been done, we will be able to repair the damage and move on..."
Victor Gao, director of China National Association of International Studies
"We hope that they will be released quickly," he said on Friday.
Japan's Kyodo news agency reported the men were preparing a bid on a project to dispose of abandoned chemical weapons from the second world war but Fujita did not confirm that.
China had told Japan that the four were being held "based on China's laws on the protection of military facilities and on criminal procedure", Yoshito Sengoku, Japan's most senior government spokesman, said, adding that Tokyo was trying to get more details through its embassy in China.
Hidenobu Sobashima, a Japanese foreign ministry spokesman, told Al Jazeera the government feels the arrest is not related to the boat collision issue.
"The Japanese will address this issue calmly. We hope the Chinese side will also address this issue calmly," he said.
Jeff Kingston, the director of Asian studies at Tokyo-based Temple University, told Al Jazeera that China had overreacted in its response to the boat captain's arrest.
"Both sides need to step back from the abyss and find a resolution to this dispute. I think eventually they will manage this crisis but we are going to go through a real rough patch and this is going to undermine trust and habits of co-operation," he said.
But Victor Gao, director of China National Association of International Studies, a government think-tank in Beijing, said the announcement of the release marks a positive development that will allow both countries to put the incident behind them.
"Even though damage has already been done, we will be able to repair the damage and move on to other important things between China and Japan," he told Al Jazeera.
"It is in China's interest as well as in Japan's interest to close ranks and co-operate with each other rather than be distracted by any unexpected incidents.
"In the future, both [China and Japan] need to be wiser and refuse to let such boating incidents deteriorate and escalate tensions between the two countries."
The US had registered top-level concern over the diplomatic feud between the Asian rivals, and urged the two sides to quickly resolve the dispute.
Barack Obama, the US president, met Naoto Kan, the Japanese prime minister, in New York on Thursday, just hours after holding talks with Wen Jiabao, the Chinese premier, against this backdrop of diplomatic tensions.
"Once again, we have reaffirmed the importance of the US-Japan alliance not only to regional stability, not only to the security of both our countries, but we believe it's one of the cornerstones of peace and security throughout the world," Obama said.