No one was injured in the firing but following the incident, there was panic and anger in the area where an anti-Citizenship (Amendment) Act (CAA) protest has been underway for over a month.
According to Deputy Commissioner of Police (DCP) Chinmoy Biswal (south-east district), the man has been identified as Kapil Gujjar, a resident of Dallupura village in east Delhi.
Soon after he fired in the air, the police overpowered and apprehended him. Bullet shells have also been recovered from the site of the firing.
A police officer present at the spot said "three bullets were fired in the air".
The local residents, however, claimed Kapil was overpowered by them and then handed over to the police.
He was allegedly "very close to the police" when he opened fire. He was standing near the second barricade which is partially open. The Shaheen Bagh protest site has four layers of barricades.
A local resident at the protest site said: "It is a major security lapse... anything can happen here. Police are doing nothing for the security of the people here who are protesting peacefully."
In a video tweeted by a TV channel, the shooter could be heard saying: "Iss desh mein kisi ki nahin chalegi, sirf Hinduon ki chalegi. (In this country, no one but Hindus can have their say)."
The people present at the protest site said he threatened protesters, warning them to vacate the site where they have been holding a protest against the CAA and the National Register of Citizens since December, before firing in the air.
The man has been taken away by the police amid tight security to an unknown place where he is being questioned, a police officer told .
The crowd wanted to rough up the youth but the police prevented the situation from getting out of hand. The people also raised slogans against the police.
On Thursday, a youth opened fire with a country-made .315 bore pistol when the Jamia students were to start their march from Jamia Millia Islamia to Rajghat. It left a journalism student, Shadab, with injuries on his arm.
( With inputs from IANS )