THE HAGUE - An international tribunal today ruled against China in a bitter row over territorial claims to the South China Sea that is likely to ratchet up regional tensions.

"The tribunal concluded that there was no legal basis for China to claim historic rights within the sea areas falling within the ’nine-dash line’," the Permanent Court of Arbitration said in a statement.

China asserts sovereignty over almost all of the strategically vital waters in the face of rival claims from its Southeast Asian neighbours.

Manila had lodged the suit against Beijing in 2013, saying China was in violation of the UN Convention on the Law of the Sea (UNCLOS), to which both countries are signatories, and that after 17 years of negotiations it had exhausted all political and diplomatic avenues.

Beijing waged a months-long campaign to discredit the panel, which it says has no jurisdiction in the multinational dispute, and it refused to take part in the case.

The Philippines welcomes a ruling by a UN-backed tribunal today that declares China has no "historic rights" in the South China Sea, Foreign Secretary Perfecto Yasay said, as he urged restraint.

"The Philippines welcomes the issuance today... on the arbitration proceedings initiated by the Philippines with regard to the South China Sea," Yasay told reporters minutes after the court in The Hague released its verdict.

One of the key issues was whether the land features in the area are islands capable of supporting human habitation -- which under UNCLOS are entitled to territorial waters and an exclusive economic zone -- or rocks, which only have territorial waters, or low-tide elevations, which get neither.

If none of the outcrops are islands, then none of the claimants to them would gain sole rights to major expanses of the waters around them.

Philippine Foreign Minister Perfecto Yasay said on Friday that Manila hoped to open direct talks with Beijing on the dispute, and presidential spokesman Ernesto Abella said today: "The top priority will be national interest."

The Philippine embassy in China has warned its citizens to beware of personal "threats" and avoid political debates. — AFP