UPDATE 14:10:

Nothing toxic was found on the road.

UPDATE 13:10:

A driver along the E4 has called in to Norran about the spill. The emergency services suspect it is a leak from a truck heading south.

Crews are currently searching for the source of the leak and attempting to identify the responsible vehicle. The substance appears to be continuing to spill southbound.

A team from Lövånger is en route to the scene to assist with the search.

– A team from Lövånger is heading north to see if they can meet up with the truck in question, says the SOS operator.

UPDATE 12:40: 

At 12:39, SOS received an alarm about a hazardous substance spill on the E4 just south of Skellefteå.

According to initial reports, the spill occurred between Tjärn and Yttervik, near Björnmyren. The Swedish Transport Administration (Trafikverket) warns of disruptions at the location.