Traffic Scotland tweeted that the accident happened on the eastbound side of the bypass, just before the Straiton off-slip.
It is understood both lanes are now open but Edinburgh Travel News recently tweeted: “City Bypass (E) - queues are right back to Hermiston Gait now from the RTC at Straiton, beginning to have an impact on Calder Road / A71, M8 (E), Frogston Road East, Oxgangs Road and Redford Road...”
The distance between the off-slip at Straiton and Hermiston Gait is approximately seven miles.
One tweeter, @LnSHarris, said that the cars have ended up in the central barrier and nearside verge.
Police were unable to provide details of how many cars were involved or if anyone has been hurt as a result of the collision.
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