Vietnam expressed its concern Tuesday over China's moving of an oil rig in the disputed South China Sea, that could potentially result in a repetition of the 2014 standoff that strained ties between the two communist neighbors, the Wall Street Journal reported. China has laid claims to almost all of South China Sea, resulting in territorial disputes with several neighboring countries.

Vietnam's Foreign Ministry spokesman Le Hai Binh reportedly said late Tuesday that China should immediately stop the movement of Haiyang Shiyou oil rig from the area where the two countries' continental shelves overlap and have not been demarcated, according to the Associated Press.

"Vietnam demands that China not conduct any drilling activities and withdraw Hai Duong 981 oil rig from this area," Binh reportedly said, using the Vietnamese name for the oil rig. "Vietnam reserves all its legal rights and interests in the area in accordance with international law."

In 2014, the movements of the same deep-water rig, HYSY 981, caused a diplomatic row between China and Vietnam after its operator, a unit of China National Offshore Oil Corp., towed it into waters claimed by the two countries. The incident sparked anti-China riots in Vietnam that left five people dead.  Hundreds of factories owned by Chinese and other foreign companies were looted and burned during the riots, the Journal reported.

This month, Vietnam accused China of violating its sovereignty by landing a plane on the disputed Spartly Islands. China responded by saying the flights were exempt from international civil aviation procedures because they took place within China’s sovereign territory. China's foreign ministry labeled Vietnam's accusations "unfounded."