Chinese Foreign Ministry Spokesman Qin Gang said Wednesday that Japan has come up with a serious provocation to China's rights by granting Japanese firms the right to drill for gas and oil in East China Sea.

In response to a question from local press, Qin said China has already lodged protest on this issue to the Japanese side and will retain the right to make further reaction.

Qin said the move by the Japanese side is a serious provocation to the rights of China and the norm of international relations.

Qin said there are disputes between China and Japan on the demarcation of the continental shelf of East China Sea. He said China has always insisted that the two sides should resolve the issue through diplomatic negotiation.

But, Qin said, the Japanese side has turned a deaf ear to the righteous proposition of China and attempted to impose its unilaterally-conceived "demarcation line" on the Chinese side.

"China has never ever recognized and will never recognize this (the "demarcation line")," Qin said.

The Japanese government on Wednesday initiated procedures to grant Japanese firms the right to conduct test drilling for potential gas and oil fields in the East China Sea, the Kyodo news agency reported.

Japan's Ministry of Economy, Trade and Industry has asked relevant authorities to review applications from companies which want to explore the fields, said the report.

A number of Japanese companies originally submitted applications to conduct test drilling in the area in the 1960s but the government shelved the applications on the grounds that demarcation of the sea area remained unsettled, Kyodo said.

Last year, Japan began conducting a survey on deep-sea resources in waters east of the "median line," a move which aroused serious concerns from China which said it would never accept such a provocative act.