Rex Phillips from the NASUWT union, which represents a large number of teachers at Cwmcarn High School, says they are "shocked and concerned by what appears to be a very serious incident" at the school yesterday.
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Mostly dry tonight with some lingering cloud around.
Bronwen Williams, 11, and her two brothers, aged 15 and 17, are all under the legal voting age in the UK.
Hundreds of people took part in a protest march in Haverfordwest today over changes to hospital services.