A Chinese survey vessel was observed operating inside Japan's exclusive economic zone off Amami Oshima Island in Kagoshima Prefecture, the said Japan Coast Guard, reported the Japan Times.

The 10th Regional Coast Guard Headquarters in Kagoshima confirmed that a patrol ship spotted the Chinese vessel about 380 kilometres west of Amami Oshima at around 6.15am. The ship appeared to be deploying a wire into the sea, suggesting possible marine research activity.

The Japanese crew issued a radio warning to the Chinese ship, stating that conducting marine surveys without prior consent from Japan is prohibited within its EEZ.

By 9:45am, the Chinese vessel had crossed the equidistance line between Japan and China to the west and exited the EEZ, according to the coast guard.