Part of the A14 was closed after emergency services were called to a two-vehicle crash near Ipswich.
Police, ambulance and fire crews were alerted to the crash in the eastbound carriageway near junction 53 at Whitton at about 2pm.
A spokesman for Suffolk police said a full carriageway closure was put in place.
The extent of any injuries is not yet known.
According to the AA Traffic Map there were lengthy delays in the area.
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