Kolkata, Jul 4 (IANS): The National Investigation Agency (NIA) on Friday filed a charge sheet indicting two Maoists involved in a Kolkata and Jharkhand-based module for waging war against the state as well as conspiracy for terrorist attacks.

"In supplementary charge sheet filed before a special court here, the NIA indicted Mohan Viswakarma and Arjun Ganjhu for offences under the Unlawful Activities Prevention Act, conspiracy to commit terrorist act and for being a member of a terrorist organisation," the agency said in a statement.

Both Viswakarma and Arjun Ganjhu are members of the Communist Party of India-Maoist which has been declared as a terrorist origination by the central government.

Viswakarma from Bihar's Imamganj was arrested by the Special Task Force of the Kolkata police from the city while Ganjhu hailing from Jharkhand's Latehar district was nabbed from Ranchi in July 2012.

Following their arrest, a large quantity of unfinished parts of about 800 hand grenades, in different stages of preparation, were recovered from a transport agency as well as various workshops in Kolkata.

Following a directive from the union home ministry, the NIA took up the probe from the Kolkata STF in April 2013.