Vietnam's central postal service has slammed China's recent issuance of stamps that they say violate Vietnam's sovereignty over the Spratly Islands in the territorially contested waters of the South China Sea.

Hanoi's demand for immediate cancellation of China's new series of stamps came just a day after it condemned Beijing's ceremonies Monday marking the "70th anniversary of the recovery" of the Spratly and Paracel archipelagoes.

The China Post on October 28 issued postage stamps depicting five lighthouses that China constructed on five reefs on Vietnam's Truong Sa (Spratly) archipelago which, Vietnam says, are still illegally occupied.

China, which claims most of the energy-rich waters of the South China Sea, through which about $5 trillion in ship-borne trade passes each year, started operating a lighthouse on one of its artificial islands there in April.

China took part of the Spratly archipelago by force in 1988, killing 64 Vietnamese soldiers who fought to protect the islands. In 1974, China took advantage of the American troops' withdrawal from Vietnam to invade the Paracel Islands.

The Vietnam Postal Service said in a statement that the stamp collection runs counter to Article 8 of the Universal Postal Union Convention.

On Wednesday, Vietnam's Ministry of Information and Communications issued a statement demanding that China respect "historical truths." Ministry spokesperson Le Hai Binh said the Chinese move could not change the fact that Vietnam has indisputable sovereignty over the islands.

This is the third time China's postal service has released stamps that Hanoi describes as a violation Vietnamese sovereignty over the Spratly and Paracel islands. In the earlier issuance of stamp sets in 2004 and 2013, China Post distributed a series of stamps featuring the islands. This time, the Vietnam Post called on China to avoid similar acts.

In response to China's move, Vietnam Stamp Club last month asked information ministry officials to issue a set of its own stamps featuring images of the Spratly and Paracel islands to reaffirm Vietnam's sovereignty.