The emergency unit at University Hospital of Wales is treating adults and children involved in the incident in Rhoose.
The unit has specialist procedures in place for dealing with serious incidents and those have been activated to care for those involved.
The priority now is treating those involved and supporting their families.
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Alexandra Lodge has been to Aberconwy, where Plaid Cymru, the Conservatives and Labour are all hoping to claim victory.
Cloudy skies to start the day, and rather windy with prolonged rainfall during the morning which will be heavy at times.
ITV Cymru Wales will publish the final poll of the Welsh Assembly Election 2016 campaign on Wednesday this week.