This is probably nothing more than an urban legend!
While transporting some mental patients from one secure institution to another in Harare, Zimbabwe, a newly hired bus driver stopped at a roadside restaurant to use the facilities. On his return to the bus, all twenty patients were gone.
Fearing the consequences of his negligence, he drove to a bus stop, where he claimed to be a replacement for the regular service. He allowed twenty people aboard and drove straight to his original destination. On arrival, he warned staff at the gates that the ‘patients’ were deluded and volatile.
The angry ‘patients’ were duly removed, sedated and incarcerated. They remained in detention for three days, until staff were able to check records and confirm their true identities.
The real patients were never found.