Scores of demonstrators in Vietnam's capital who gathered to support an international tribunal's rejection of China's claims in the South China Sea were hustled away by police before their rally started.
The protesters were meeting Sunday at the landmark Hoan Kiem Lake - a common spot for demonstrations in Hanoi - when police forces descended on them.
Vietnam has a history of clamping down on protests, fearful the rallies could stir dissent.
The Hague-based Permanent Court of Arbitration recently ruled against China in a case filed by the Philippines about China's historical claim to about 90 percent of the South China Sea, one of the world's busiest shipping lanes.
China refused to participate in any of the hearings and said it would not comply with any decisions by the tribunal.
Six governments have overlapping territorial claims in the South China Sea: China, Vietnam, the Philippines, Taiwan, Malaysia and Brunei.
China bases its claim on a so-called "Nine Dash line," which dates back to the 1940s and stretches deep into the maritime heart of Southeast Asia, covering hundreds of disputed islands and reefs, rich fishing grounds and oil and gas deposits.