Two people have been transported to hospital following a crash in Gilmore this afternoon.

Just after 2pm, ACT Emergency Services responded to a two-vehicle head-on crash on the Monaro highway south of Isabella Drive.

Firefighters had worked for nearly an hour to free a person trapped inside one of the vehicles, the person was then assessed and transported to hospital by ACT Ambulance Service paramedics in a serious condition.

The person in the other vehicle was also treated by paramedics and transported to hospital in a stable condition.

Monaro Highway remained closed for several hours while emergency services remained on the scene.

An investigation into the circumstances surrounding the collision has commenced. Any witnesses, or people with dash-cam footage of the collision, are urged to contact Crime Stoppers on 1800 333 000 or via the website. Quote P2126369.

Information can be provided anonymously.