Activists Koo Sze-yiu (3rd L) and Fang Xiao-song, who are part of the group of Chinese activists who went to the disputed Senkaku or Diaoyu islands, hold a Chinese national flag in front of a banner as they arrive at Hong Kong airport August 17, 2012. Japan on Friday sent home the first group of Chinese activists detained after landing on an island claimed by both Tokyo and Beijing, a move China welcomed but at the same time warned its neighbor against further "escalation" in tension. The banner reads, "Successful landing on Diaoyu islands, Activists show their ambitions, Welcome back". REUTERS/Tyrone Siu (CHINA - Tags: POLITICS CIVIL UNREST)