video transcript

Boats are unloaded as officials from the Tokyo city government prepare to survey a chain of disputed islands. The local Tokyo authorities say they are researching the area with a view of buying four islands claimed by both Japan and China. Called Senkaku in Japan and Diaoyu in China, the island chain has proven controversial in recent weeks. Activists from both nations caused a diplomatic storm by landing on the islands. And now 25 experts are assessing the area, despite being denied permission to land by Japan's national government. SOUNDBITE: JAPANESE SURVEY TEAM LEADER, SEIICHIRO SAKAMAKI, SAYING (Japanese): "The Tokyo metropolitan government is looking to buy these islands and so if people from the metropolitan government don't come down then it's hard to even talk about it. So in that sense, we're here to see the area. Additionally, we want see if we can figure out the basics of how the island could be utilized." As the team began surveying, China called the move "illegal". Quoting the Foreign Ministry, Chinese state broadcaster CCTV said action in the area would harm bilateral ties. The territorial dispute is one of many dogging relations in Asia, as nations row over areas potentially lucrative in gas reserves.