Ten persons were killed when a pick-up van rammed into a tree on Puranpur highway under the Gajraula police circle here on Thursday morning.
Seven others were seriously injured in the accident and have been admitted to a hospital.
According to reports, the van was moving at a high speed when the driver apparently dozed off and the vehicle hit a tree.
Seventeen passengers in the vehicle were returning from Haridwar after taking a holy dip in the Ganga river.
While eight persons died on the spot, two succumbed to their injuries later.
Chief Minister Yogi Adityanath has expressed grief at the loss of lives and directed officials to ensure proper treatment to the injured.
The bodies have been sent for post-mortem.