China, Malaysia locked in S. China Sea standoff: Report

China and Malaysia are locked in an ongoing standoff over hydrocarbon exploration in the South China Sea, according to a US think tank report published on Wednesday.

A Chinese vessel "harassed" a drilling rig and supply ships off Malaysia's coast last week, said the report by the Center for Strategic and International Studies' Asia Maritime Transparency Institute (AMTI).

"China Coast Guard [CCG] ship 5402 harassed a drilling rig and its supply ships operating just 44 nautical miles from Malaysia's Sarawak State on November 19," read the report.

"Malaysia deployed a naval vessel in response, which continues to tail the 5402."

According to the report, the incident seems to have come on the back of "two weeks of increasing tensions between the CCG and RMN [Royal Malaysian Navy] in the area."

The AMTI report said the Chinese ship departed from China's Hainan province on Oct. 30.

"It stopped at China's artificial island bases on Subi and Fiery Cross Reefs before taking up station at Luconia Shoals in Malaysia's exclusive economic zone on November 2," the report said.

"CCG ships have maintained a nearly constant presence in the area in recent years facilitated by the nearby logistics hubs in the disputed Spratly islands."

The South China Sea-a crucial passage for a significant portion of the world's commercial shipping-is bordered by Brunei, Cambodia, China, Indonesia, Malaysia, the Philippines, Singapore, Taiwan, Thailand, and Vietnam.

Beijing claims roughly 90% of the sea, which encompasses an area of around 3.5 million square kilometers (1.4 million square miles).