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.
More top news
Leicester City council is facing legal action at the High Court today over claims it discriminated against the Jewish community.
400 jobs are to be created after water companies Severn Trent Water and United Utilities announced they are moving to Stoke city centre.
The family of a teenage boy who died after a hit-and-run in Leicester are urging the public to help find the driver of the car.