A car has flipped on St Saviour's Hill, closing the road.
Police are assessing two other vehicles at the scene of the incident.
It is unknown if there have been any major injuries.
Islanders are unable to use the road from the bottom of St Saviour's Hill, until further notice.

The incident is believed to have happened at around 2:00 pm on Friday (13 December).

Two Jersey charity leaders become MBEs in King's Birthday Honours
Election voter turnout revealed
States members sworn in as Chief Minister discusses Ministerial options
Man (36) found guilty of child sexual abuse
Healthcare campaigners make a stand as new States is sworn in
Jersey students heading to university to receive Meningitis B vaccine
Farnham to remain Chief Minister
Hole in road causes gridlock in St Helier