Aidan Kenny, 34 and unemployed, was arrested after armed police surrounded his home in Royal Oak Road, Wythenshawe, Manchester, yesterday afternoon. His children were found lying in pools of blood.
Witnesses said Lesley Kenny, 10, was lying behind the front door. Her brother Joseph, aged eight, was in the living room. Greater Manchester Police said a man had been arrested following the killings. He may be charged today.
Mike Allen, deputy director of Manchester City Council social services department, said last night: 'The family are known to us and we are investigating our involvement.'
Identification of the children was carried out last night by their mother, Bridget, who was at work when the attack took place. A third child, nine-year-old Tricia, was being cared for by relatives; she was at school during the killings. Joseph had been sent home from the Sacred Heart primary school for fighting. Lesley was off sick.
The family's neighbours, Joan Ryan, 32, and Karl Ryan, 34, said Mr Kenny called at their house at about 12.30pm.
They went to the house and called an ambulance. During the 25 minutes before it arrived, some teachers from a nearby infants school vainly tried to give the children first aid.