An air ambulance has been scrambled to an incident in Hitchin.
A photograph shows an Essex and Herts Air Ambulance landing near Kingshott School and the A602 Stevenage Road.
The helicopter and its crews arrived on the scene at around 5.45pm.
A spokesperson for the air ambulance said that unit AW162 - which is based at North Weald, Essex - had been called to help ground crews in Hertfordshire.
They said that further details will be unavailable until crews return to the base.
The East of England Ambulance Service has been contacted for comment.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here