State police are investigating a multi-vehicle crash on Route 1, which backed up northbound traffic south of the C&D canal Thursday afternoon.

The investigation thus far has determined that the crash occurred at 1:33 p.m. Aug. 17 on southbound Route 1 near Biddles Toll Plaza and involved multiple vehicles including an overturned tractor-trailer. Injuries have been reported in the crash; however, the exact number and extent of the injuries is unknown at this time.

Both the northbound and southbound EZ Pass lanes at the toll plaza have been closed to traffic and commuters are asked to find alternate routes of travel.

 The investigation into this crash is in its early stages. More information will be released after the investigation.