Commercial Fixed Wing
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Confusion; Distraction
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance; Ground Event / Encounter Other / Unknown
General None Reported / Taken
Procedure; Company Policy; Environment - Non Weather Related; Human Factors
We pushed back and were starting an engine when the tug driver told us there were three more passengers coming on a bus we called ops to verify and then shut down the engine and had the tug pull us back into the gate.  We opened the doors and loaded the three passengers.  I then went and asked the tug driver if we were getting a new pin. He said no they were included in the original count.  We then called ops to verify the passenger count. We had the Flight Attendant do a head count and the numbers matched. We closed the doors and pushed the rest of the flight was uneventful.This was caused because of the multiple buses that are used to move passengers due to the COVID-19 social distancing. We were told all passengers were onboard. I will have the flight attendant do a head count for all flights that are done with remote parking.
Air Carrier Captain reported being pulled back to the gate to receive 3 passengers who were not on the flight yet due to being transported in a different bus for COVID-19 distancing.