Five new deaths were reported on Wednesday (Oct 21) alone, but authorities had no plans to suspend the vaccination programme, unless investigations, including post mortems, revealed a link, which preliminary findings had not.

"We have reviewed whether it is appropriate to continue the vaccination or better to suspend and wait for the results," health official Kim Joong-gon told a briefing.

"We came to the conclusion that the deaths had no direct relations with the vaccination given the limited data we have now and without detailed post mortem reports."

Kim said a preliminary investigation into six victims revealed five had underlying conditions.

"It makes it hard for us to put out a categorical statement," Vice Health Minister Kim Gang-lip told a briefing on Wednesday about the deaths, which include a 17-year-old boy and a man in his 70s.