Part of the west African country is locked down by the authorities and vaccines are taken to the area to avoid new infections.
Two people have tested positive for Ebola in Guinea, months after the country was declared free of the deadly virus.
Both patients are from the same village, Korokpara, where three people from the same family have died in the past few weeks, suffering from suspected symptoms.
“All of the sick people have been taken to the Nzerekore treatment centre,” an official said.
Government spokesman Damantang Albert Camara said: “Vaccines have been taken to the zone to avoid new infections.
“The area has been locked down.”
It is unclear how the villagers contracted the virus, but the area had previously resisted attempts to tackle the disease.
The cases emerged after the World Health Organisation (WHO) declared neighbouring Sierra Leone’s latest outbreak was over.
The world’s worst recorded Ebola epidemic is believed to have started in Guinea, which killed about 2,500 people up until December last year, when the WHO said the virus was no longer being actively transmitted.
In total more than 11,000 people have died since the outbreak began in 2013, mostly in Guinea, Liberia and Sierra Leone.
The WHO has warned the Ebola virus could reemerge at any time as it can remain in the eyes, central nervous system and bodily fluids of some survivors.
The organisation said in a statement: “Strong surveillance and emergency response capacity need to be maintained, along with rigorous hygiene practices at home and in health facilities and active community participation.”