Four persons arrested in connection with the security breach in Parliament have been charged under the anti-terror law UAPA besides sections of the Indian Penal Code while key conspirator Lalit Mohan Jha was held on Thursday evening, police sources said.

On Wednesday, Lalit came with the four others to Parliament. When they got only two passes, Lalit decided to take the mobile phones of all four -- Sagar, Manoranjan, Neelam and Amol -- with him.

During interrogation, it was revealed by the four accused that they wanted to enact revolutionary Bhagat Singh's action of throwing bombs inside the Central Assembly during British rule in India, the sources said.

Police said the accused had planned to throw pamphlets in Parliament after using the smoke bombs, adding that they had also bought tricolours.

The case was registered against the four -- Sagar Sharma (26), Manoranjan D (34), Amol Shinde (25) and Neelam Devi (37) -- under UAPA sections 16 (punishment for terrorist act) and 18 (punishment for conspiracy, etc.) and IPC sections 120B (criminal conspiracy), 452 (trespass), 153 (wantonly giving provocation, with intent to cause riot), 186 (obstructing public servant in discharge of public functions) and 353 (assault or criminal force to deter public servant from discharge of his duty) at the Parliament Street police station, police sources said.

The police are also questioning Gurugram resident Vishal Sharma and his wife as the four arrested accused stayed at Sharma's residence on Tuesday night.

Lalit Mohan Jha, a key accused in the Parliament security breach incident, was arrested on Thursday evening, sources said.

"Lalit Jha came to Kartavya Path Police station where he was arrested. He was handed over to Special Cell which is investigating the incident," an officer said.

Offences punishable under the stringent Unlawful Activities (Prevention) Act are non-bailable. An official said the security agencies have not found connections with any terror group so far.

The four arrested on Wednesday were associated with a social media page named 'Bhagat Singh Fan Club'.

"So far, the four accused claimed to have been self-motivated and they were planning and executing the whole incident on their own," a senior officer said.

Police sources said the scope of the probe was expanded with the role of a few more people suspected for Wednesday's security breach.

Soon after the security breach incident, Jha recorded a video of Neelam and Amol shouting slogans and releasing yellow coloured smoke from canisters outside the Parliament building and sent it to Neelaksh Aich, the founder of a Kolkata-based NGO, police said. Jha is stated to be a part of the NGO.

On Thursday, the four arrested accused were remanded in seven days of police custody by a city court.

As they were being produced before a Patiala House court on Thursday, reporters asked them on whose directions they enacted the security breach, Manoranjan replied "No one".

During the arguments, the prosecution accused the four of indulging in an act of terrorism and said they tried to incite fear. "It was a well-planned attack on Parliament," police said.

The prosecution said their custodial interrogation was necessary to unravel the actual motive behind the incident and find out if some other people were also involved.

They hid (smoke) canister in their shoes," police told the court, adding that special shoes were made in Lucknow which needs to be probed.

"They need to be taken to Mumbai, Mysore and Lucknow for probe," the court was told.

Meanwhile, Vishal was questioned again Thursday but later allowed to go in the evening, said an officer, adding "he may be called again for further questioning." Sharma and his wife have not been given clean-chit so far, police sources said.

In a major security breach, Sagar and Manoranjan on Wednesday afternoon, jumped into the Lok Sabha chamber from the public gallery during Zero Hour, released coloured smoke from canisters and shouted slogans before being overpowered by some MPs.

Around the same time, Amol and Neelam sprayed coloured smoke from canisters while shouting "tanashahi nahi chalegi" outside Parliament premises.

Names of two organisations have also emerged in the investigation of the Special Cell and their roles are being examined, a senior official said, adding all the accused are giving the same answers to the investigation team.

Lalit, Sagar and Maoranjan had about a year ago met in Mysuru where they made a plan to barge into the Parliament. They later added Neelam and Amol to the plan.

Lalit took the lead and instructed Manoranjan to do a recce of all entry points of the Parliament during the Monsoon Session, the official said.

"In July, Manoranjan came to Delhi and went inside Parliament on a visitor pass issued in the name of an MP. There, he got to know that the frisking of shoes does not happen," the official said.

Stringent measures were put in place in and around the building on Thursday, with police and the Parliament security staff thoroughly checking the credentials of those entering the complex.

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