Another rhino died after it got stuck in water hyacinth while three deer and a python were run over on the highway, he said.
Vasu said only herds of elephants and buffaloes, apart from a few deer, had managed to cross over to neighbouring Karbi Anglong while most of the other animals were taking shelter on highlands within the Park.
He said the situation within the Park was critical and "we are preparing for the worst". Additional staff from other departments like social and territorial forestry had been roped in and people engaged to monitor the movement of animals across National Highway 37.
Assam Forest Minister Pradyut Bordoloi was camping in the Park to review the situation.