A group of Chinese activists sail from Hong Kong - bound for a chain of disputed islands in the Pacific Ocean.<br/> <br />They are aiming to assert China's sovereignty over the isles, which are also claimed by Taiwan and Japan.<br/> <br />Activists chanted "Down with Japanese Militarism" as they journeyed towards the Diaoyu Islands, which are known as Senkaku in Japan.<br/> <br />The group said several boats from China will converge on the chain - though in the past Hong Kong has prevented other protest vessels from leaving port.<br/> <br />It's the latest swipe in a jousting match over islands off the coast of eastern Asia.<br/> <br />Last week, South Korea's president touched off a diplomatic firestorm when he visited an island also claimed by Japan - one believed to sit atop massive oil reserves.