Hanoi: Vietnam has protested against China`s plan to open up foreign oil bids in a disputed area in the South China Sea, adding to tensions in the region.
According to The BBC, the Foreign Ministry said the move was ``illegal`` and a serious ``violation of Vietnam`s sovereignty``.
The ministry said that the oil blocks are ``deep inside Vietnam`s exclusive economic zone and not a contested area``.
China`s CNOOC (China National Offshore Oil Corporation) oil company said that nine offshore blocks were open to foreign bids this year. Chinese Foreign Minister Hong Lei also said that the tender was ``normal business activity`` and asked that Vietnam ``not further complicate and aggravate the dispute``.
"This is absolutely not a disputed area. [CNOOC``s move] is illegal and of no value, seriously violating Vietnam`s sovereignty," Vietnam`s Foreign Ministry said in a statement. It added that China`s move is "causing tension" in the South China Sea.
The country`s state-owned oil company, PetroVietnam, also called on international firms to boycott the bid invitation. The South China Sea, thought to be rich in oil and natural gas reserves, has been a source of maritime conflict between several countries.