Wildlife officials in Thailand have discovered the carcasses of five more wild elephants downstream from a waterfall where the bodies of six other elephants were found on Saturday.

The animals were originally thought to have died while trying to save each other after falling into a waterfall at Khao Yai national park, but a drone being used to investigate the deaths later identified five further carcasses, including that of a three-year-old calf.

Only two elephants in the herd are known to have survived the fall at the 200-metre-high Haew Narok waterfall in Thailand's mountainous north-east