Mamata Banerjee was at her home when the incident took place.
An armed man was arrested on Friday near Chief Minister Mamata Banerjee's residence in Kolkata's Kalighat area, police said.
The man, identified as Sheikh Noor Amin, was arrested after he allegedly tried to drive a car that had a 'police' sticker towards Ms Banerjee's residence on Harish Chatterjee Street, they said.
Ms Banerjee was at home when the man, in a black coat and tie, was intercepted at the crossing of Hazra Road and Harish Chatterjee Street, they added.
"He was carrying firearms and a kukri. Ganja and identity cards of different agencies, including the BSF, were found with him. He wanted to meet the CM. Our officers intercepted him when he was trying to enter Harish Chatterjee Street," Kolkata Police commissioner Vineet Goyal said.
"Considering the fact that the CM is a Z-category protectee, this is a serious issue," he added.
Initially, the man said he is from Anandapur area of the city, then he claimed he is from Paschim Medinipur, Mr Goyal told reporters.
Officers of the Kolkata Police's Special Task Force (STF), Special Branch and the Kalighat police station were interrogating him, another officer said.
The black car, which Amin was driving, was seized, he said.
A preliminary investigation found that Amin is a resident of Aliganj village in Kotwali police station area of Paschim Medinipur district, police said.
A case has been filed against him under different sections of the IPC, including those related to impersonating public servant and criminal conspiracy, besides the Arms Act, they said.
Expressing concern over the incident, leader of opposition Suvendu Adhikari of the BJP demanded the immediate removal of the officer-in-charge of the Kalighat police station and the police commissioner.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)