The ex-leader has been rallying crowds since Wednesday as he makes his way down the major road from capital Islamabad to his party’s stronghold in the eastern city of Lahore, weeks after he was deposed by the Supreme Court.
“A 13-year-old boy who had come to see the rally was hit by a car in the convoy,” Sajid Ali, head of the local Lalamusa police station, told AFP.
An investigation had been launched, he said.
Railways minister Khawaja Saad Rafique called the teenager “the first martyr of this movement for democracy” in an address to the thousands-strong crowd in nearby Gujrat.
One of the vehicles in the motorcade hit and killed the boy as he crossed a divider on the road, the minister said.
Sharif said in his Gujrat speech he would personally visit the boy’s home “and try to help his family for life”.