Vietnamese soldiers on Truong Sa Lon Island in the Truong Sa (Spratly) Archipelago
The first Chinese tour ship to visit the Paracels (Hoang Sa) Islands that Vietnam claims sovereignty over set sail on Sunday despite Hanoi's objection to the plans earlier this month.
China's sending the cruise ship to the Paracels was the latest in a series of unilaterally provocative actions in the area.
Last month, a Chinese ship shot flares at four Vietnamese fishing boats from Quang Ngai Province that were fishing in their traditional fishing grounds in the Paracels, a move that Vietnam criticized as "inhumane and dangerous".
Up to 100 passengers paid a ticket price between 7,000 yuan ($1,135) and 9,000 yuan for the four-day voyage, which is set to become a monthly or twice monthly trip if the maiden trip proves successful, AFP quoted the Global Times as saying.
Only passengers in "good health, which includes having a normal weight" are permitted on the trip, the newspaper added, in a report which cites the Shanghai Morning Post.
The plan to allow cruise tours follows rapid development of infrastructure in a new city -- Sansha -- along with the establishment of an army garrison in the Paracels last year, AFP said.
On April 5, Vietnam's National Border Committee under the Ministry of Foreign Affairs protested China's plans to sail the cruise ship, saying that Vietnam has "incontestable" sovereignty over the Paracels and Spratlys (Truong Sa) islands.
The cruise ship plans is against the spirit of the talks in which Beijing committed to fully follow the Declaration on the Conduct of the Parties in the South China Sea (DOC), the committee said in a statement.
It demanded that China cancel such plans.
A named commentary in the Global Times defended the decision to allow tourists to visit the islands, which are known as Xisha in China, AFP reported.
"China's Xisha tourism has nothing to do with its neighboring countries," it quoted Ju Hailong, a research fellow at the Institute of Southeast Asian Studies at Jinan University, in the southern city of Guangzhou, as saying.
"Those who want to manipulate China's moves to make trouble are not admirers of international law and regional security."
China and four members of the Association of Southeast Asian Nations (ASEAN) Vietnam, the Philippines, Malaysia and Brunei are embroiled in sovereignty disputes over the East Sea, internationally known as the South China Sea.
China illegally claims sovereignty over 80 percent of the East Sea.
The waters are thought to hold vast untapped reserves of oil and natural gas that could potentially place China, the Philippines, Vietnam, and other claimant nations alongside the likes of Saudi Arabia, Russia, and Qatar.
In 1974, taking advantage of the withdrawal of the American troops from the Vietnam War, China invaded the Paracel Islands. A brief but bloody naval battle with the forces of the then US-backed Republic of Vietnam ensued.
Vietnam's behemoth northern neighbor has illegally occupied the islands ever since. But a post-1975 united Vietnam has never relinquished its ownership of the Paracel Islands and continues to keep military bases and other facilities on the Spratly Islands.
Analysts say China will continue to develop the Paracels to demonstrate that it is in effective occupation of the islands and is exercising administrative control.
"The next move by China will be to impose its annual unilateral fishing ban in the South China Sea above 12 degrees north latitude, or the waters around the Paracel Islands," said Carl Thayer, a maritime analyst with the University of New South Wales in Australia.
"Chinese civilian authorities may step up their arrest of those they consider 'illegal fishermen'," Thayer said.
Vietnam, as part of its efforts to maintain sovereignty over the Paracels and Spratlys, is closely following the claim filed by the Philippines against China, which is set to be arbitrated by a UN tribunal.
Manila is seeking a United Nations ruling on the validity of Chinese claims to the resource-rich sea, with a possible unfavorable verdict for China seen as a test of its willingness to yield over territorial disputes, AFP reported Friday.
On April 24, the President of the International Tribunal for the Law of the Sea (ITLOS) officially appointed arbitrators to serve as members of the tribunal.
In response to questions from the media regarding Vietnam's position on the case, Foreign Ministry Spokesman Luong Thanh Nghi said Friday that "Vietnam follows with interest the developments of this tribunal."
Analysts also say that the major development affecting the East Sea dispute is the action by the Philippines to seek the Arbitral Tribunal to make an award on the legal issues it has raised.
"This initiative should be given every chance of succeeding," Thayer said.
"Vietnam should not undertake any action that would give China the opportunity to create a distraction. China appears on the diplomatic back foot and is struggling to find a way to respond."