The accident took place last night when an Agra-bound tractor-trolley, carrying electric poles, overturned on the expressway after it was hit from behind by a private bus, DSP Surendra Singh said.
The poles were scattered on the road after the collision after which an SUV, coming from Delhi, also rammed into the bus, he said.
Three persons travelling in the SUV were killed on the spot while another of its occupant succumbed to injuries on the way to S N Medical College in Agra, he said.
The deceased have been identified as Rahul, Saurabh, Vijai Singh and Prince Kumar. They were in the age group of 20-30 years and hailed from Dumariya Ganj area of Siddharth Nagar district in Uttar Pradesh, the DSP said.
The driver of the tractor and the bus fled from the spot after the accident and a hunt is on to nab them while their vehicles have been seized.