Firefighters were called to Clatterbury Lane in Clavering just before 8.30am on Thursday where a bus and car had crashed.
The bus had also hit a tree branch causing extensive damage to the roof, Essex County Fire and Rescue Service confirmed.
Photos of the scene show the bus roof had fallen onto the road, blocking all traffic.
The East of England Ambulance Service said three children were assessed at the scene and two were taken to Addenbrookes hopsital “for further assessment and care”.
Three ambulances, four Hazardous Area Response Team vehicles, two ambulance officer vehicles and Essex and Herts Air Ambulance responded.
Nobody was trapped in either the car or the bus.
— Star Radio (@StarCambs) September 21, 2023
Essex Police said: “We were called to reports of a collision in Clatterbury Lane, Clavering, at about 8.15am on Thursday 21 September.
“At the scene officers found a bus and a car had collided.
“We have closed the road while we continue to make the scene safe.
“Drivers are advised to check before they travel and plan accordingly if their journey is affected.”