All the four accused involved in the Parliament security breach incident have been sent to police custody for seven days, officials said on Thursday.

The accused — Manoranjan D, Sagar Sharma, Amol Shinde and Neelam –have been charged under the stringent Unlawful Activities (Prevention) Act (UAPA) and several other relevant sections of the Indian Penal Code (IPC).

They were produced before a Delhi court earlier Thursday. The police had sought 15 days custody for questioning them. However, special judge Hardeep Kaur granted the police seven days custody.

The police told the court that given the serious nature of the breach, it needs to be probed whether any terrorist organisation was involved in the incident.

On Wednesday, Manoranjan and Sagar gained entry into the visitor’s gallery of the Lok Sabha using passes issued by Parliament on recommendation by Mysore BJP MP Pratap Simha.

During the Zero Hour, the men jumped into the well of the House and set off smoke canisters they carried inside Parliament by hiding them in their shoes. They were thrashed and overpowered by MPs before being taken into custody by the Delhi police.

Two of their associates – Neelam and Amol – could not get the visitor’s pass and protested outside the Parliament complex by setting off another smoke canister.

There are reports that police have also detained two more persons – a couple – from Gurgaon for allegedly giving them shelter before the breach episode.

According to police sources, the incident was well planned and the accused conducted a recce of Parliament to find out ways to smuggle in smoke canisters. It was during their recce that they found out that shoes of visitors are not checked.

The BJP MP, meanwhile, gave an explanation to Lok Sabha Speaker Om Birla and reportedly told him that the father of Manoranjan had requested for the passes and that he did not have any idea about their intentions.

The Opposition has demanded action against the BJP MP. They created a ruckus in Parliament and also demanded resignation of Union Home Minister Amit Shah over the incident.