The Welsh Government has announced schools across Wales will close amid the coronavirus outbreak.
The education minister said schools across Wales will close for statutory provision of education at the latest on 20 March.
In a statement following the announcement, Ms Williams confirmed summer exams for GCSEs and A levels will not go ahead due to the school closures.
She said that grades for year 11 students will be based on assessments and exams already completed, with the same happening for year 13 students due to complete A levels.
She also said emergency provision will be on offer for students receiving free school meals.
Boris Johnson later announced schools in England will also close from Friday, as well as Scotland, making it the largest school shut down since universal education was introduced.
Following the announcement, the director of teachers union NAHT Cymru Laura Doel, said it welcomes the decision but “details of how we can support vulnerable children and children of key workers are yet to be finalised".
“Schools play a pivotal role as part of the social fabric of our communities and we will work with Welsh Government to make sure the support systems are in place to ensure key workers can remain in work", she said.
“As a union, we will continue to work with Welsh Government to ensure that we all fulfil our civic duty to keep Wales open.”
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