The crash happened just before 4pm close to the junction for the turn-off for Harvey’s Point on the N15.
Diversions are in place but people can still travel through the Gap.
There are believed to be two people injured in the crash but the extent of their injuries are not known.
Crash scene investigators are at the scene of the crash.
The diversions will remain in place until further notice.
We will bring you more on this story as get it.