A police party led by a head constable was on patrolling duty from Jaleb Chowk to Manak Chowk late on Friday night when the police rifle cartridges were found to be missing, Mahendra Singh, Deputy Commissioner of Police, Jaipur North said.
"The cartridges went missing from the van. It came to light when one of the members checked the cartridges after the vehicle halted at a place," he said.
Authorities have sounded alert across the state.
There were four policemen in the van when the cartridges went missing, Singh said, adding, the matter is being probed.