The fate of the world's most famous panda preserve remained unknown on Tuesday, more than a day after China's worst earthquake in three decades closed off the remote, mountainous area from the rest of the world. The Wolong National Nature Reserve and panda breeding centre is the only place in the world where the rare animals can be seen in such large numbers. But Chinese officials and zoo officials overseas are worried about the centre's 100 or so pandas, whose home is close to the heart of Monday's 7.9 earthquake in central Sichuan province. More than two dozen British and American tourists who were thought to be panda-watching in the area also remained missing. Pandas are such a symbol of China that the loaning of them to other countries as peace offerings has been described as "panda politics."