An autorickshaw driver brutally assaulted a four-year-old boy by lifting him by his legs and slamming him to the ground before smashing his head on an iron rod following an argument with the minor's father in Maharashtra's Palghar district, police said on Tuesday.

The incident took place in a housing society at Vasai on Monday night, following which the accused was arrested, they said, adding that the critically-injured child is battling for life in a hospital, reported PTI.