Kolkata, Feb 3 (IANS) West Bengal Chief Minister on Sunday alleged that National Security Advisor Ajit Doval was giving instructions to the CBI at the behest of Prime Minister Narendra Modi and BJP President Amit Shah as she began a sit-in at the city centre "in a bid to save the federal structure of the country".

"I am sorry to say National Security Advisor Ajit Doval is giving instructions to the agency. He is implementing what PM Narendra Modi is asking. He should tell the people that it is not correct," an agitated Banerjee said.

Her reaction came after an evening of high drama in front of Kolkata police commissioner Rajeev Kumar's official residence on Loudon Street when a group of CBI officers were stopped by city police personnel from approaching Kumar's house.

The Kolkata police personnel also forcibly took the federal probe agency officers to a police station after bundling them into several vehicles.

"I will start a dharna (sit-in demonstration) at Dharamtala (at the city centre) to save the federal structure of the country," she said. Minutes later she began the sit-in.