Tonight's open night at St Patrick's College in Maghera has been postponed. Two of its junior pupils remain critically ill after being hit by a car near Randalstown.
It is understood the children were involved in the collision with an Audi A3 after getting off the school bus.
The incident happened on the Staffordstown Road, at its junction with Greenan Road at around 4.40pm.
The car is said to have remained at the scene, but police are appealing for witnesses to come forward.
The school has also asked for prayers following the incident.
St Patrick's College has put out a statement:
Our whole school community has been greatly saddened by the news that two of our junior pupils were critically injured in a road traffic accident on their way home from school yesterday. Please remember them and their family in your prayers at this very difficult time.
The Open Night planned for this evening (Wednesday 18 January) has now been postponed as has the Open Day on Saturday 21 January.
Woman dies in hospital after road crash in Co Fermanagh
Police name man found dead in Bangor
Education Authority boss hits out at criticisms of public services
Man in 90s dies following Co Down road crash
Police to increase patrols after second incident of shots being fired in Belfast