A U.S. media outlet reported that China declared a "no-sail zone" in waters that fall within South Korea's exclusive economic zone(EZZ).

Newsweek reported that a regional branch of the China Maritime Safety Administration(MSA) in Jiangsu Province banned ships from entering three designated areas in the southern Yellow Sea from 8 a.m. Thursday to 8 a.m. on May 27, local time.

According to a map disclosed by the outlet, most of the three areas lie within the provisional measures zone(PMZ), an area where the South Korean and Chinese EEZs overlap, while two of them only cover South Korea's EEZ.

Earlier, China's installation of three structures on the western side of the PMZ without prior notice sparked concerns in South Korea that it may be trying to expand its influence in the Yellow Sea and establish a basis to make territorial claims.

Beijing, for its part, has claimed that the structure supplements two other submersible structures as part of its aqua farming facility.