BRUSSELS, Aug 27 (Reuters) - Production of Moderna COVID-19 vaccines at a plant of partner Rovi in Spain can continue after an initial assessment, the European Union drugs regulator said on Friday, as it continues its investigation of a contamination incident.

On Thursday Japan suspended the use of 1.63 million doses of the Moderna vaccine, with the company saying contamination could be due to a manufacturing issue on one of the production lines at its contract manufacturing site in Spain run by Rovi .

"COVID-19 vaccine production in Rovi is able to continue, following a preliminary risk assessment of the information received so far," the European Medicines Agency told Reuters in a statement on Friday.

"An investigation into the root cause is ongoing. EMA will be able to provide more information as the investigation progresses," it added. (Reporting by Francesco Guarascio @fraguarascio; Editing by Catherine Evans)