Deepak (31) was found lying in a pool of blood near the gate of the primary school in Swaroop Nagar around 4:30 pm. He was rushed to a nearby hospital where doctors declared him dead, they said.
He was a contractual teacher at the school run by the North Delhi Municipal Corporation. No arrest has been made so far in connection with the killing, said a senior police officer.
"The CCTV footage shows the attackers were in a Grand i10 car," said Milind Dumbere, DCP, Northwest Delhi.
The killing could be the fallout of a personal enmity. A probe is underway, they said.