Doctors of the World, an NGO, released figures showing that more than 250,000 children in Greece are not privy to public healthcare, meaning they don’t have access to the necessary vaccinations.

The NGO’s General Secretary Liana Mailli said the number is an approximation as there is no official data on inoculations for Greece despite the EU rules concerning this. She said the figures are based on estimations two years ago, and said that it is higher due to the dramatic rise of refugees and migrants sneaking into the country.

She warned of “an explosive situation” that sits as a ticking time bomb with the real risk that diseases which had been eliminated, such as diphtheria, tetanus, pertussis, measles and polio, will reappear.

After the dismissal of a large number of doctors, she claimed, the state-run health insurer EOPYY and other health facilities “have been decimated and cannot serve the insured, let alone uninsured children.”