Parts of both Adelaide Avenue and Melrose Drive have been closed after two separate motor vehicle incidents across Canberra this morning.

Adelaide Avenue northbound is closed from the first off ramp on State Circle due to a motor vehicle accident that has left a 15-year-old boy in a critical condition in Canberra Hospital. Adelaide Avenue is now reopened after being closed for much of the day.

All northbound traffic is being diverted onto the first off ramp at State Circle. Motorists are advised to avoid the area. The closure is expected to be in place for some time.

Melrose Drive southbound is closed at Corinna Street due to a vehicle fire in the pedestrian underpass. All southbound traffic being diverted onto Corinna Street. Police are said to be treating the fire as suspicious. The two lanes are closed on Melrose Drive southbound between Corrina Street and Hindmarsh Drive due to damage at the pedestrian underpass. The lanes and pedestrian underpass will be closed until further notice