The number of reported cases of measles in the Bible Belt region has gone up to 67, the public health institute RIVM said on Friday.

The true figure is likely to be far higher because not all patients will go to their family doctor, the RIVM told news agency ANP.

The outbreak is largely affecting children aged four to 12 who attend orthodox Protestant schools. Most of the reported cases are focused on the Gisbertus Voetiusschool in the Brabant town of Andel where 50 out of 245 children have been diagnosed with measles, ANP said.

Many of the country’s strict Protestant communities do not vaccinate their children on religious grounds.