FOUR passengers have been trapped inside their vehicles following a huge pile-up on a major Hampshire motorway.

The crash, involving at least eight vehicles, happened in between junction 12 and 13 of the M3 shortly after 8pm.

At least one of the passengers is though to be seriously injured.

Police have closed the northbound carriageway between junction 12 and 14, and diversions have been put in place.

Officers are advising motorists to avoid the area if possible.

A spokesman for the police said the motorway was expected to be closed for some time.