The National Highways: South-East account tweeted: ‘Four miles of congestion, almost back to #M27. Ambulance Services are just about to leave scene.’
Reports say that traffic is also building on the southbound lane.
A spokesman for Hampshire Constabulary said: ‘We were called at 2.05pm today to a collision involving four vehicles on the northbound carriageway of the M3 between junctions 11 and 12.
‘Injuries have been reported to us.
‘Two lanes of the northbound carriageway were closed while the vehicles are recovered.
‘We remain at the scene.’