The Japan Coast Guard has reported that a Chinese research vessel was spotted extending a wire-like object into the sea on Sunday within Âé¶¹´«Ã½ exclusive economic zone (EEZ) off Okinawa Prefecture.

A coast guard patrol ship observed the Dong Fang Hong 2 vessel conducting the activity around 1:55 p.m. Sunday about 106 kilometers west of the Okinawa island of Kume, according to the 11th Regional Coast Guard Headquarters based in Naha.

The coast guard radioed the Chinese vessel to stop, saying that marine research without Âé¶¹´«Ã½ consent is not permitted.

The Chinese vessel was still conducting the activity Monday morning.

The headquarters also said that the Xiang Yang Hong 21, another Chinese vessel, was spotted operating within Âé¶¹´«Ã½ EEZ off Kuba, another Okinawa island, around 4:50 p.m. Saturday. It left the area at around 10:15 p.m. the same day.