China on Saturday greeted the return of a fishing boat captain who had been detained by Japan by demanding an apology and compensation from Tokyo and restating its claim to the disputed waters where he was seized.
"This was an action that gravely violated Chinese sovereignty and the human rights of a Chinese citizen, and the Chinese government strongly protests," said a Foreign Ministry statement issued after the captain, Zhan Qixiong, flew back to China after being released by the Japanese authorities.
He had been detained near islets in the East China Sea claimed by both countries. The Chinese statement said China's claim to the islands was "indisputable."
"It is unlawful and invalid for Japan to detain and investigate the boat captain and to take any legal measures against him," said the statement, issued by the official Xinhua news agency. "Japan must offer China an apology and compensation over this incident," said the statement.
The captain flew out of Ishigaki airport in southern Japan aboard a chartered plane, Kyodo news agency said.
Japanese and U.S. officials had said the captain's release would ease Sino-Japanese tensions.
A prosecutor from Naha city on Japan's southern Okinawa island said Friday that the decision to release the Chinese captain, whose trawler collided this month with two Japanese patrol boats took into account the importance of Sino-Japanese ties.
Prime Minister Naoto Kan said the decision to release Zhan was made by authorities after "considering the nature of this incident from all angles" and based on Japanese law.
"China and Japan are important neighbors with important responsibilities in the international community," he said in New York, where he attended the U.N. General Assembly.
"In order to further grow our mutually beneficial relationship based on strategic interests, I believe it is necessary for Japan and China to handle matters calmly," Kan told reporters.
Kyodo quoted a Japanese national resources and energy agency official late Friday as saying it was highly possible that China had started drilling in a gas field in the disputed waters of the East China Sea. But the report also cited a foreign ministry official as saying there was no confirmation.
The United States welcomed Japan's decision to release the Chinese captain, saying it had defused a potentially dangerous situation.
"This was a Japanese decision to make and we're just hopeful that with the release of the ship captain, tensions will recede and the countries in the region will get back to normal business," U.S. State Department spokesman P.J. Crowley said.