One of the buses might skidded off the track leading to a collision with another bus in Jalandhar.
Four people were killed and over a dozen injured when two buses collided in Shahkot area in Jalnadar on Saturday, police said.
The collision took place between a JSK bus and an Orbit bus, they said. Orbit buses is co-owned by Punjab's Deputy Chief Minister Sukhbir Singh Badal.
The deceased have been identified as Pal Singh from Dharamkot, Vinod Kumar from Jalandhar and Gurbhej Singh from Shahkot while the identity of the woman is yet to be ascertained, police said.
"Those injured have been admitted to a hospital," SP Harmon Singh said.
Police were yet to ascertain the cause of the accident. "It has been raining heavily in Jalandhar since morning."
"One of the buses might have skided off the track, leading to the collision. However, we are yet to ascertain the cause of the accident," said Mr Singh.
The orbit bus was going from Jalandhar to Muktsar while the GSK bus was going from Moga to Pathankot.