The Korea Disease Control and Prevention Agency (KDCA) said on Friday it would press on with a wide flu vaccination program aimed at heading off complications from the coronavirus, after reviewing more than two dozen cases of deaths that have raised public concern.

A review had shown no direct link between the vaccination and 26 deaths that were investigated, the KDCA said in a statement, adding it planned to meet on Saturday to review additional analysis.

The toll of deaths among people who have been vaccinated reached 36 on Friday, sparking calls from doctors and politicians for a halt to the program, which aims to vaccinate about 30 million of the country's 52 million population.

Some 20 initial autopsy results from the police and the National Forensic Service showed that 13 died of cardiovascular, cerebrovascular and other disorders not caused by the vaccination, while seven are undergoing additional examinations, KDCA said.

Both the forensic agency and police were not immediately reachable for comment.

Prime Minister Chung Sye-kyun expressed condolences to the families of those who died, calling for a thorough investigation to verify the exact cause of deaths.

"So far experts said there was a low possibility that the shots and deaths were related but many citizens remain anxious," he told a meeting.

The rising death toll has fueled debate about whether the program, which is free for some citizens, should be suspended. The country's largest grouping of doctors called for a halt until the safety of the vaccines is confirmed, while a major vaccine society said inoculation should continue as no relation to the deaths has been found.