A school boy died while undergoing treatment on Thursday after sustaining a head injury while travelling on a school bus.

According to police, a 13-year-old boy from Samakhushi, Kathmandu was injured in the head after being hit by a tree as he had pulled his head out of the bus window on Wednesday afternoon.

The injured child was rushed to the Maharajgunj-based Tribhuvan University Teaching Hospital for treatment.

The incident happened at Kathmandu Metropolis-2, Lazimpat while the boy was returning home on the school bus.

Police said they have detained the bus driver, adding a further investigation was underway.