Nigeria, Aug. 27 -- A worker at Frankfurt Airport in Germany has died of malaria in a rare outbreak believed to have been caused by infected mosquitoes brought into the country on an aircraft.

Five other airport workers have also contracted the disease and are receiving medical treatment, according to the BBC.

The airport operator, Fraport, confirmed the death on Wednesday. "Sadly, we must confirm that one employee has died as a result of the infection," a Fraport spokesperson told the BBC.

The outbreak is being investigated by Frankfurt's Public Health Department, with officials trying to establish how the workers became infected.

The BBC reported that the six infected workers are men who work in different areas and perform different...