Fifteen monkeys died from dehydration after their rivals prevented them from accessing water during a brutal 45-degree heatwave in India.
Over a dozen Rhesus monkey corpses were found dotted around a group of forest caves in Madhya Pradesh, India, on Thursday and Friday.
Investigators believe a battle may have broken out between competing monkey groups after they refused access to the dwindling water supply.
District forest officer PN Mishra said: "We're probing all possibilities, including the possibility of conflict between groups of monkeys for water in the forest which led to the death of 15 monkeys from a 30-35-strong group of monkeys living in the caves."
Locals claim to have seen a group of larger monkeys chasing away another group that had tried to drink from pockets of water near the dried-up riverbed.
The bigger monkeys may have then forced the surviving animals to remain confined in the caves as temperatures soared.
An autopsy revealed that at least some of the monkeys died from multi-organ failure following heatstroke, NDTV reported.
Around five or six different monkey groups live in the forest area which has seen the river bed dry up and caused huge competition between the primates.
"This is rare and strange as herbivores don't indulge in such conflicts," Mr Mishra said.
Extremely hot weather has already claimed the lives of 17 people across the sub-continent and has resulted in farmers being restricted access to vital water supplies for their livestock.
