The forest officials said that the bio-repellent was extracted from a plant and was much harmless but still effective against the elephants.

Various “volunteer-spirit tourist” groups comprising 43 off-road trucks were not allowed to enter Kanchanaburi’s Thung Yai Naresuan wildlife sanctuary during December 8-9 because they failed to adhere to the rules and conditions for gaining access, according to sanctuary chief Wichien Chinnawong.