The accident happened on the westbound carriageway between junctions 4 for the A666 and J3 for Bolton Road at around 9.50am.
One lane was reported to be closed but the incident has since cleared, says Highways England.
Another accident on the motorway happened shortly after at 11.20am on the eastbound carriageway.
One vehicle is reported to have driven off the carriageway into a hedge.
Nobody was injured in any of the incidents.