The Delhi Police has registered a case under the stringent Unlawful Activities (Prevention) Act in connection with the Parliament security breach, officials said on Thursday.

In a major security breach on the anniversary of the 2001 Parliament terror attack on Wednesday, two persons — Sagar Sharma and Manoranjan D — jumped into the Lok Sabha chamber from the public gallery during Zero Hour, released yellow gas from canisters and shouted slogans before being overpowered by some MPs.

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Around the same time, two other accused — Amol Shinde and Neelam Devi — sprayed coloured gas from canisters while shouting “tanashahi nahi chalegi” outside Parliament premises.

Police said the four were part of a group of six people who planned the incident.

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The officials said the case has been registered under 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) and UAPA sections 16 and 18 at the Parliament Street police station.