They also damaged an ambulance and injured its driver and a compounder.
According to the villagers, the police arrived about an hour late at the site of the accident.
This morning, Sanjay Meena (18) was on his way with his uncle to Kotputli town on a motorcycle when a dumper hit them, police said.
While Meena died on the spot, his uncle Pappu was seriously injured and rushed to a Jaipur hospital.
When four policemen reached the spot in a jeep, a mob poured some inflammable and tried to set it on fire, the police said.
The policemen escaped narrowly, they said.
After additional police force was rushed to the spot the mob pelted stones at them in which two policemen received minor injuries, police said.
The situation was later brought under control with additional deployment.
22 people have been detained in this connection, they added.
