At least 10 commandos of Central Reserve Police Force (CRPF) belonging to its elite Commando Battalion for Resolute Action (COBRA) battalion were killed in a Naxal IED attack in a jungle of Aurangabad district in Bihar on Monday.
Five other soldiers were also injured in the blast.
Following the blast, gunfire broke out between the two sides in which three Naxalites were killed.
The bodies of three dead rebels were recovered, an official said.
A search operation was launched after the attack under the supervision of top CRPF officials.
The casualties might rise as some of the jawans of the COBRA were critically injured in the gun battle.