A Chinese research ship and its escort, which operated for nearly a month in Vietnam’s exclusive economic zone (EEZ) in the South China Sea and prompted a rare protest from Hanoi, left those waters late on Monday, June 5.

Chinese vessel Xiang Yang Hong 10 began sailing in Vietnam’s EEZ on May 7, at times flanked by a dozen ships, regularly crossing gas and oil fields operated by Russian companies, according to vessel-tracking data.

The Chinese vessel and its entourage of more than half a dozen ships began their journey back to China’s Hainan island, leaving Vietnam’s EEZ around midnight, the data showed.

Asked about the movements of the ships, China’s foreign ministry did not comment about the return to Hainan.

“It is legitimate and legal for Chinese research vessels to carry out normal research activities in waters under its jurisdiction, and there is no such issue about entering the exclusive economic zones of other countries,” Chinese foreign ministry spokesperson Wang Wenbin said at a regular press conference on Tuesday.

Vietnam’s foreign ministry did not respond to requests for comment.

Chinese ships ignore Vietnam demand to leave area close to Russian-run gas fields

Under international law, ships are allowed to sail through foreign EEZs, but unauthorised surveys are not permitted and China’s operations in the South China Sea have long been problematic for countries in the region, as Beijing claims most of the energy-rich sea, including foreign EEZs.

In a rare public protest on May 25, Vietnam’s government urged the Chinese research ship and its escort to leave the country’s EEZ after a visit to Hanoi by senior Russian official Dmitry Medvedev.

The incident comes amid what Washington has described as “growing aggressiveness” from Beijing, following close encounters between US and Chinese ships and jets in the area. Senior US and Chinese officials held talks in Beijing on Monday that both parties called constructive.

At 0300 GMT on Tuesday, the Chinese research ship was seen approaching Hainan, said Ray Powell, who leads Stanford University’s Project Myoushu on the South China Sea.

Vietnam’s fisheries surveillance ships turned back after the Chinese vessel and its escort left Vietnam’s EEZ around midnight Vietnam time, Powell added.

Vietnam-based researcher Van Pham, who heads independent non-profit South China Sea Chronicle Initiative (SCSCI), confirmed the ships had left Vietnam’s EEZ but warned that Hainan was not the research ship’s home port, and after a break there it could resume activities in the South China Sea.

Vietnam demands Chinese ship leave its exclusive economic zone

– Rappler.com