The car carrying social activist Medha Patkar was stoned by a mob after it hit a child on National Highway 34 near Kaliachak in Malda district on Monday.
Patkar was travelling to North Dinajpur district when her car hit a seven-year-old boy on the highway, 25km from Malda town, at slow speed in a congested market area, slightly injuring him, the police said.
Soon after, angry local residents surrounded the vehicle and began hurling stones.
However, before the situation could worsen, the police arrived in strength and dispersed the mob. It then escorted the car and Patkar to safety.
The boy was taken to a local hospital and later pronounced out of danger. The car was not damaged except for some dents caused by the stones, the police said.