Motorists are being advised to avoid the Mount Rule Road area after a crash earlier.
Traffic is said to be heavy after the incident, which happened shortly after 1.30pm.
Officers say the crossing point onto Eyreton Road is shut.
Emergency service vehicles are also using the TT access road, which is said to be causing delays there.
Government advice following spike in data breaches
Plans for four-foot flood walls at Ramsey harbour
Garage blaze in the early hours of this morning
Art anarchists "hiding gold bars" in Douglas this week
No cases of terror financing through charities
You can now adopt an ambulance
Case for horse tram tracks 'under final review'
Council spends more than £1m on beads for cavities