The incident took place last evening when Shashikant (19) and sister-in-law Susheela (40) were taking an infant to a doctor in Kalyanpur.
Their bike was hit by a speedy truck from behind near Naramau toll-tax barrier leading to on-the-spot death of Shashikant and Sushila while the infant was injured.
The bodies have been sent for post mortem, he said adding, the infant was rushed to hospital where her condition was stated to be critical.
