The 17-year-old male arrested after two girls were stabbed is believed to be their brother.
One of the victims is thought to be aged 16 and police now believe the other victim is 10-years-old.
A woman in her 40's was also stabbed. The condition of the three is said to be 'serious'.
A baby discovered at the house was unharmed.
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The forecast means train services on West Coast mainline will be limited to 50mph for safety reasons between the West Midlands & Birmingham.
Storm Doris brings wet and windy weather.
Wet and stormy tomorrow. Some disruption likely.