China has lodged a protest after two local Japanese assembly members landed on one of the Diaoyu Islands, saying the move seriously infringed on China's territorial sovereignty.

Foreign Ministry spokeswoman Jiang Yu said on Friday, that the Diaoyu Islands have been an integral part of the Chinese territory since ancient times.

According to reports, two members of the municipal assembly of Ishigaki in Okinawa Prefecture, landed on an islet of the Diaoyu Islands on Friday morning.

Jiang said China has lodged a solemn representation and voiced strong opposition to the Japanese government.