The driver of the truck that crashed into the tanker has been taken to hospital while police have launched a preliminary investigation into suspected reckless driving.

“It’s a pretty normal measure to take in a situation like this. We need to impound the vehicle, which is a coercive measure meaning you have to start a preliminary investigation,” police spokesperson Stefan Gustafsson told the TT news agency.

However, there are no prime suspects at the moment.

“No, absolutely not. Quite the opposite, we’re going to examine why the accident occurred,” he said.

It remains unclear whether or not other vehicles may have been involved in the fiery crash, which closed traffic on the main transit artery in both directions on Wednesday.

“But we have no information indicating that that is the case and we should have found something at this point,” said Gustafsson.

“The explosion was powerful, however, and there may only be a pile of metal left, so we’ll have to see whether or not there is anything from another vehicle. We’ve got investigators on the scene.”

Emergency crews had finished their work by Wednesday afternoon, handing clean-up work over to the Swedish Transport Administration (Trafikverket).

“Retrieval work also remains so that we can deal with what remains of the tanker,” said Gustafsson.

The tanker truck was carrying both diesel fuel and gasoline at the time of the accident.

The E6 remains closed at the site of the accident and isn’t expected to reopen before 7am Thursday morning after new asphalt has been laid.

The stretch of road is a heavily used transit artery in southern Sweden, carrying an average of 2,000-4,000 heavy vehicles per day.

According to Sweden’s Civil Contingencies Agency (Myndigheten för samhällsskydd och beredskap – MSB), blazes with such massive flames and thick smoke are rarely seen in Sweden.

Since 2006, the agency has registered 81 roadway accidents with hazardous materials, not including incidents involving on- or off-loading.

One such accident involved an explosion, while fires started in thirteen others incidents.