The driver of the tractor, proceeding towards Mat, took a u-turn and started driving in the opposite direction after coming to a blind spot on the expressway.
On way back, the tractor hit a motorcycle at Kilometre No 101 in Mat police station area, killing Munnu and Salim of Etawah, a police officer said.
The driver tried to sped away when it hit another bike at Kilometre No 106 in Yamuna Paar police station, killing Sonu (25) and injuring Shivam (18) of Noida, the officer said.
After the second accident, the driver fled the spot leaving the vehicle. A hunt for the tractor driver is on, the officer said.