TOKYO - China has lodged solemn representations to Japan over its moves of infringement and provocation regarding the Diaoyu Islands, the spokesperson of the Chinese embassy in Japan said on Sunday.

The China Coast Guard vessels have taken law enforcement measures to protect their rights in accordance with the law, said the spokesperson.

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According to media reports, five Japanese National Diet members, including Tomomi Inada, the acting secretary general of the ruling Liberal Democratic Party, who participated in a so-called "investigation group" organized by the Ishigaki city government, entered the waters near the Diaoyu Islands for "inspection," and claimed that they should go ashore to investigate.

The spokesperson said that the Diaoyu Dao and its affiliated islands are China's inherent territory, and China has the firm resolve and will to safeguard its territorial sovereignty and maritime rights and interests.

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China strongly urges Japan to abide by the four-point principled agreement between the two nations, stop all political provocations, on-site disturbances and public sensationalism, return to the right track of properly managing disputes and differences through dialogue and consultation, and avoid further escalation of the situation, the spokesman said.