The IED weighing three kg was placed in a steel container and kept below a bridge in Mosam village, said police.
"The explosive is said to be planted by naxalites to mark their presence in the area," SDPO-Aheri Gajanan Tompe told PTI.
The 9th Battalion of CRPF in Aheri had received information about the IED being kept below a bridge in the village, said Tompe.
The information was passed on to the BDDS team which later defused the IED.