The carcasses of five more wild elephants have been discovered downstream from a waterfall where the bodies of six elephants were found at the weekend.
The dead elephants were discovered by a drone being used to investigate how the first six elephants plunged to their deaths at the Haew Narok – Ravine of Hell – waterfall in Khao Yai National Park in north-eastern Thailand, said Sompote Maneerat, spokesman for the national parks and wildlife department.
Park officials said the first group of elephants appear to have died while trying to reach a dead calf. The newly discovered victims are thought to have come from the same herd.
The ravines usually fill up with gushing water during the rainy season.
With the death toll now at 11, Mr Maneerat said this is the highest number of elephants to die in a single incident in Khao Yai.
Eight elephants died at the same waterfall almost 30 years ago.
The elephant population at the park is estimated to be about 300.