The terrorists fired upon the CRPF vehicle and ran towards a school, according to news channel India Today.
CRPF inspector general Ravideep Sahi said the security forces had cordoned off the area to nab the ultras.
Yadav said constable driver Nisar Ahmad is undergoing treatment in the hospital.
Two CRPF personnel have sustained injuries in the attack. He hailed from Gorakhpur district of Uttar Pradesh.
Reports suggest that millitants have taken positions in the DPS building.
He, however, said the combing and search operation is going on.
CRPF personnel retaliated but there was no immediate report of any casualty on the militant side.
LeT spokesman, Dr Abdullah Ghaznavi its men attacked on the CRPF party.
According to CRPF officials, "CRPF Sub-Inspector sitting on the front seat and the driver were hit by bullets as terrorists opened fire from the front, shattering the front glass of the vehicle".
"A sub-inspector of the CRPF was killed and two CRPF troopers injured in this attack", police said.
The incident happened near a Delhi Public School and it is feared that the militants might be hiding in the school complex which has four huge buildings in the compound. "He also confirmed all the members of the school staff were safely evacuated by the forces".