Children in Wales have been urged to stay at home and keep away from their friends in order to stop COVID-19 from spreading.
Education minister Kirsty Williams made a direct plea to children and young people saying they had an important role to play in protecting the most vulnerable from catching the virus.
16 people have now died of coronavirus in Wales and there have been 418 confirmed cases, though Public Health Wales warns the true number of cases is likely to be higher.
Ms Williams spoke at a press conference on Monday morning after a weekend which saw people visit tourist spots like Snowdonia National Park in huge numbers, despite the advice for people to socially distance.
"My message to children is that I understand that the weather has turned after a really rotten winter and ironically we seem to have had the best weather for many, many months," she said.
"I know you want to be outside and hanging around and playing outside with your friends.
"I am really sorry but you cannot do that in these circumstances and my appeal to all children and young people is to please keep yourself safe by staying at home, playing in your garden and not mixing with your friends at this time.
"I know that is hard to do but we need you to do it to keep other people in your family and in your community well.
"You as children are not powerless in this situation, you as children have the power to help us slow the spread of this disease and you can do that by staying at home and finding different ways of communicating with your friends."
Ms Williams said this meant no socialising with friends, no sleepovers and no playdates.
The minister also refused to rule out a complete lockdown across Wales and said the Welsh Government would continue to be guided by its scientific advisers.
"This Government will take all necessary steps to ensure we get through this crisis," she said.
"People don't need to wait for the Government to actually enforce that.
"This Government has been absolutely crystal clear with people about their responsibilities at this time.
"People should stay at home wherever possible; they should practise self-isolation if that is the public health guidance for their particular set of circumstances and people need to socially distance.
"At the end of this people will need to look themselves in the mirror to know they did the right thing."
Ms Williams' message came as schools officially closed their doors to the majority of pupils, but remained open to take care of the children of key workers and those who are vulnerable.
School leaders issued a plea for parents to keep their children at home unless "absolutely necessary."
The National Association of Head Teachers (NAHT) expressed concern that too many parents are trying to keep their children in school, meaning attempts to stop the spread of COVID-19 could fail.
Paul Whiteman, general secretary of the NAHT, said: "As many children as possible should stay away from school tomorrow [Monday].
"To do otherwise will risk the health of your family and the successful response to Covid-19. Please do not confuse ‘Dunkirk Spirit’ with recklessness.
A number of councils including Powys, Flintshire, Rhondda Cynon Taf and Cardiff Council took the decision to close its play areas in an effort to ensure social distancing guidelines are being adhered to.
In a statement, Cardiff Council said, "The risk of transmission from child to child on play equipment is thought to represent too great a risk to the public as we seek to slow the transmission of COVID-19.
"Cardiff's parks will remain open at this time. We understand the role they can play in aiding well being through the outbreak."
Flintshire Council said it has requested other organisations who manage similar open spaces – such as Town and Community Councils - to do the same.
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