A minor crash is causing delays on the A12 in both directions between Saxmundham and Wickham Market.
Police were told of the collision, involving a Fiat and a MG, at 4.20pm.
A force spokesman said no-one appeared to be injured but because the vehicles needed removing from the road congestion was increasing.
Recovery of the vehicles is due to take place shortly, he added.
Another crash on the A12, near Woodbridge, has been causing congestion. Police were called to the three-vehicle crash, again described as minor, at 4pm.
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