Officers were called to a service station on Long Road in Canvey Island following reports of a taxi driver being robbed and threatened with a gun.
The victim was unharmed but left shaken. A 20-year-old man and a 25-year-old man, both from from Canvey Island, have been arrested on suspicion of robbery. They remain in custody.
Chief Inspector Daniel McHugh said: “Incidents like this are extremely rare but I can reassure residents that we have multiple teams working on this investigation.
“We don’t believe that there is any wider risk to the community and our officers, including specialist search officers will be in the area today to continue enquiries.
“Anyone with any information is asked to contact us to assist with this investigation.”