The incident took place yesterday when the four, riding on three motorbikes, reached a petrol pump near Bambori village with 12 barrel guns and country made pistols, SHO Mangrol Police Station Rameshawar Parihar said.
The four robbers opened-fire when Bhuvnesh Cheepa, working as sales man at the petrol pump, protested against the robbery, the SHO said, adding, Cheepa received bullet injury on his right thigh in the incident.
The robbers fled with Rs 40,000 in cash, he said.
The police have sounded an alert at check-posts across the district but the unidentified persons are still at large, the SHO said, adding, a case of loot has been lodged against the four unidentified persons.