Dien Bien Phu billboard in Saigon

This billboard in downtown Saigon, opposite the city Opera House, implores the people to "follow the traditions of Dien Bien", referencing the historic communist victory over the French at Dien Bien Phu, 60 years ago. The battle of Dien Bien Phu marked the end of French colonialism in Indochina. The bottom of the billboard reads "defend the sovereignty of the seas and the islands of Vietnam" - referring to the long running dispute with China over islands in the South China Sea - known in Vietnam as the East Sea. While Vietnam marked the Dien Bien Phu anniversary on May 7, the Chinese navy was escorting an oil rig into waters claimed by Vietnam. China, a key supporter of the Viet Minh campaign at Dien Bien Phu, now claims vast swathes of the South China Sea as its territory and is in dispute with a number of countries. Relations with Vietnam and the Philippines are especially tense. The Chinese move prompted protests and riots in parts of Vietnam. Rioters targeted Chinese commercial interests. Taiwanese, Singaporean and other foreign businesses were also destroyed in what has been the most serious civil unrest in decades.