"We are basing our fighter aircraft at Hindan and will continue to have the detachment there till the Republic Day parade, as there are intelligence inputs of a 9/11-type aerial terror attacks," IAF officials told PTI here.
IAF's Hindan fighter detachment will comprise of MiG-21 Bisons from the Ambala air base and MiG-29s from Adampur and Halwara air bases in Punjab. These aircraft will be based there till Republic Day in turns.
The MiG-29s are a twin-engine air defence aircraft, whereas the Bisons are upgraded ground attack variant of the MiG-21 fighters.
Officials said the IAF considered the Bisons to be "more than enough" to handle the kind of threat from rogue flying objects by the IAF.
"We are not expecting any attack from Pakistani fighter aircraft, but from a small or medium-sized aircraft operated by terrorists and to tackle the threat from such flying objects, the MiG-21 is more than enough," they said.
A week before the Republic Day parade, the MiG-29s would return to the base for keeping the capital's skies secure.
"The MiG-29s will be placed at the base about a week before January 26 when the threat perception is the highest," IAF officials said.
On Republic Day, IAF's helicopter gunships will fly over Delhi to take on any threat, if need be.
The IAF, after receiving inputs about the possibility of a possible aerial terror strike, has been taking various steps like deployment of fighter aircraft, surface-to-air missiles and highly-sophisticated 'Aerostat' radars to protect Delhi from such strikes.