The M6 is closed, and Gardaí are at the scene of what are believed to be two separate crashes at Junction 3 Rochfortbridge, in the eastbound lane of the M6.
The accidents happened shortly before 3 pm.
A number of people have been brought by ambulance to the Midland Regional Hospital with injuries described as "serious but not life-threatening".
Motorists are being advised to avoid the area if possible.
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