The country’s health minister Remy Lamah told news agency AFP officials are “really concerned” about the deaths.
The 2013-16 epidemic, which began in the African country, killed 11,300 people in the region, with the majority of cases reported in Guinea, Liberia and Sierra Leone.
National Health Security Agency head Sakoba Keita told local media the four deaths from Ebola occurred in the southeast region of Nzerekore of Guinea.
One of the victims was a nurse who fell ill at the end of last month and was buried earlier this month.
Mr Keita said: “Among those who took part in the burial, eight people showed symptoms: diarrhoea, vomiting and bleeding.
“Three of them died and four others are in hospital.”
Since the 2016 epidemic, the World Health Organisation has closely monitored each Ebola outbreak, treating a recent one in the Democratic Republic of Congo as an international health emergency.
Earlier on Sunday, WHO chief Tedros Adhanom Ghebreyesus said the UN health agency had been informed of two suspected cases of the deadly disease in Guinea.
He tweeted: @WHO has been informed of two suspected cases of Ebola in Guinea-Conakry.
“Confirmatory testing underway.
“@WHOAFRO and WHO country office supporting readiness and response efforts.”
In November, authorities in DR Congo had declared an end to the country’s latest Ebola outbreak.
This has been the country’s eleventh outbreak of the deadly disease, killing 55 people from the 130 confirmed cases.
The widespread use of vaccines to fight Ebola, which were administered to more than 40,000 people, had helped bring the disease under control.
But on Thursday, fresh Ebola outbreak fears were sparked when the WHO confirmed a resurgence.
Last week, the country confirmed its third Ebola case in the North Kivu province.
The case was found in Butembo, a city which has a population of over one million people and was the epicentre of a major outbreak of the disease that was declared last June.
Provincial health minister Eugene Nzanzu Salita said: “We are in a meeting to gather all the information on the investigations done around this case.”
On Friday, the health ministry and the WHO said in a statement that 1,200 doses of the Ebola vaccine arrived in Butembo.
The statement added health workers are training vaccinators and tracing more than 100 contacts in the districts of Biena and Katwa.
The Ebola virus is spread through contact with body fluids and causes severe vomitting and diarrhoea.
It has a much higher death rate than coronavirus but unlike that disease, it not transmitted by asymptomatic carriers.
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