A new Chinese cruise ship has embarked on its maiden voyage to the flashpoint Paracel Islands in the South China Sea, which Vietnam calls the East Sea, state news agency Xinhua said on Friday.

That was the latest effort by Beijing to bolster its claims in the strategic waterway. The Changle Princess sailed from Sanya on the southern Chinese island province of Hainan on Thursday afternoon with 308 passengers on a four-day voyage, Xinhua said.

The new ship can carry 499 people and has 82 guest rooms with dining, entertainment, shopping, medical and postal services on board, it added.

Tourists will be able to visit the three islands in the Crescent group of the Paracels, Xinhua said.

China has previously said it plans to build hotels, villas and shops on the Crescent group and has also said it wants to build Maldives-style resorts around the South China Sea, though it is unclear if foreigners will ever be allowed to visit.

Vietnam has not immediately reacted to the latest ship's voyage but Hanoi has repeatedly protested such similar actions, dismissing them as a breach of its maritime sovereignty. The first cruises from China to the Paracels were launched by Hainan Strait Shipping Co in 2013.

In 1974, taking advantage of the withdrawal of the American troops from the Vietnam War, China invaded the Paracels. A brief but bloody naval battle with the forces of the then U.S.-backed Republic of Vietnam ensued.

China has illegally occupied the islands ever since. But a post-1975 united Vietnam has never relinquished its sovereignty.

China claims 90 percent of the potentially energy-rich South China Sea, through which passes about $5 trillion of trade a year. The Spratlys, which Vietnam calls Truong Sa, are claimed in part or whole by China, Vietnam, the Philippines, Malaysia, Brunei and Taiwan.

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