Around 400 Vietnamese protestors took to the streets in Hanoi and Ho Chi Minh City on Sunday in a peaceful march against Beijing's claims to two disputed islands in the South China Sea, AFP reported. Police kept the protestors, who shouted anti-Chinese slogans, away from Chinese diplomatic missions. An earlier protest, which took place close to the Chinese embassy saw Beijing issue a rebuke to Hanoi. Tensions first arose on December 9 after China set up a county-level government unit covering 2.6 million square kilometers, most of it ocean. The area includes the Spratly and Paracel archipelagos, which comprise more than 100 islets claimed in full or part by China, Vietnam, the Philippines, Malaysia, Brunei and Taiwan. The islands are considered strategic outposts in the South China Sea and have potential oil and gas reserves and rich fishing grounds.