A man is to appear at a special sitting of Bray District Court at 9pm this evening following an alleged assault in Co Wicklow.
The incident happened at Blainroe yesterday evening, shortly after 7.30pm.
Gardaí and emergency services attended the scene, around 4km south of Wicklow town.
All four children were taken to Tallaght Hospital, including two who were airlifted.
They children are believed to be aged between 3 and 11, and were described as being in a serious condition today.
The scene has been preserved for technical examination, and an incident room has been set up in Wicklow Garda Station.
A man in his mid-30s has been arrested in connection with the incident, and is being held at at Wicklow Garda Station under section 4 of the Criminal Justice Act.
Gardaí have also appointed a family liaison officer.