There were somber scenes today after a beloved panda named Chuang Chuang died in a Thai zoo.

The male panda had celebrated his 19th birthday in August and was in good health at the Chiang Mai zoo in northern Thailand.

But yesterday (September 16) he had finished eating his favourite bamboo shoots before walking around his enclosure and collapsing.

The body of Chuang Chuang, or Xuang Xuang, is now being held at the zoo while staff wait for Chinese officials to carry out a post mortem examination.

Staff believe that Chuang Chuang could have choked on his food or died from old age.

Zoo director Wutthichai Muangmun said: ''Chuang Chuang has not had any illness previously and he had celebrated his birthday on August 6.

''The cause of the death has not yet been proven. We are having to wait for experts from the People's Republic of China to investigate.

''As for the primary cause, it is expected that food particles may have been stuck in the throat or he may have died naturally.''

Chuang Chuang arrived in Chiang Mai with female panda Lin Hui in October 2003. The bears were gifts from China to show closer relations between the two countries.

Pandas have a life-span of around 20 years in the wild.