Four children have been killed and half a dozen others injured after a horrifying car crash where a vehicle ploughed through an after-school facility.

The tragic incident unfolded in Illinois on Monday when a car crashed through a group of people and a school building. The car careened into the crowd outside the YNOT after-school daycare on Breckenridge Road in Chatham around 3.20pm.

The vehicle struck multiple people outside before smashing into the building and exiting on the other side. Three of the victims who lost their lives were outside during the incident, while the fourth was inside the building.

Several victims were taken to the hospital after the crash, including one who had to be airlifted for emergency treatment. Their ages have not been disclosed, but they are all believed to be between four and 18 years old.

The driver of the vehicle was seen being apprehended by police officers, uninjured, and is currently undergoing evaluation in hospital, reports the Mirror.

Families gathered at the nearby Chatham Baptist Church while emergency services continued their recovery operations at the scene. 

Local Governor JB Pritzker issued a statement saying, "My administration is closely monitoring the crash in Chatham. As we continue to learn more, please follow the guidance of all local authorities.

"Let's wrap our arms around the community tonight as we receive updates on the situation."