The two men, who managed to enter the Lok Sabha hall from the visitors' gallery on Wednesday, have been identified, said the sources, adding that a team of the forensic science laboratory (FSL) has collected samples.
They have been identified as Manoranjan, a resident of Karnataka and Sagar Sharma.
Besides these two, the Delhi Police also detained two other protesters, a man and a woman, who were protesting with colour smoke flares outside Parliament, an official said.
The duo has been identified as Neelam, a resident of Hisar in Haryana and Amol Shinde, a resident of Latur, Maharashtra.
The Deputy Commissioner of Police (New Delhi) Pranav Tayal said the 'protest' incident happened outside Parliament in front of Transport Bhawan which is a running road.
Meanwhile, teams of Intelligence Bureau, Special Cell and other central agencies have also reached the Parliament Street police station where Neelam and Amol are detained.
"It will be clear after questioning if the two men caught inside the Lok Sabha and other two caught outside are linked to each other," said the sources.
Two youths who jumped in the well of the Lok Sabha raising slogans "Kaala Kanoon Nahi Chalega, Gundagardi nahi chalegi".
"It's not linked to any terror attack," said the sources.
A video circulating on social media further revealed one of the individuals using a yellow-coloured flare, skillfully navigating from seat to seat within the hallowed halls of the Lok Sabha.
Astonishingly, the smoke flare was cleverly concealed in the individual's shoes, escaping the scrutiny of initial security checks.
A forensic science laboratory (FSL) team has also collected the sample of colored smoke flares used outside and inside the Parliament.
"Marking and photography have been done on the spot and samples have been collected for further investigation. We will test the chemicals used in smoke flares," said the sources.