Vietnam has dismissed China's accounts of its test flights to an island in disputed waters, saying it received no prior information as claimed by a Chinese Foreign Ministry spokesman.

China Foreign Ministry spokesman Hong Lei told reporters Monday that China's three test flights to Fiery Cross Reef — one of seven South China Sea features where China had carried out extensive land reclamation — were state aviation activities and had no restrictions under international law. Hong said that Beijing had informed Vietnamese aviation authorities and Foreign Ministry about them.

Hong also said that Vietnam had failed to see "the professional, technical and civil nature of China's inspection and test flights."

Vietnam Foreign Ministry spokesman Le Hai Binh rejected the statement as a "wrong position," saying Vietnamese authorities did not receive any information from China. He said in a statement posted on the ministry's website late Tuesday that China's flights had affected security and aviation safety in the South China Sea.

Binh said the flights violated Vietnam's sovereignty over the islands, and demanded that China stop any future flights and refrain from such actions.

China said it conducted three test flights earlier this month to the airstrip, one of the three built on artificial islands reclaimed by China over the last nearly two years.

Vietnam and China both claim the Paracel Islands and the two along with the Philippines, Malaysia, Brunei and Taiwan claim all or parts of the Spratlys, which sit on potentially oil and gas rich resources and occupy one of the world's busiest shipping lanes.

China's recent increasing assertiveness has caused serious concerns among countries in the region and the United States, which backs freedom of navigation and overflights in the South China Sea.