While one piece of ivory was 18 inch long and weighed 1.2 kg, the second piece was 16 inch in length and weighed 1 kg, said Laxmidhar Behera, forest range officer of Bisoi.
Four tribals were nabbed by the forest personnel along with the ivory pieces near Kaliami village under Bangiriposi police station area, he said.
It was suspected that the gang poached elephants inside Similipal National Park to get the ivory. Behera added.