THERE are fears several people have died in an explosion at a Norwegian dairy plant, a local news agency reports.

The blast occurred yesterday afternoon in Fredrikstad, in the country's southeast.

Rescue service spokesman Ola Vaage told the NTB news agency that several people are feared to have died or been seriously injured in the blast.

Rescue workers, ambulances and a helicopter were dispatched to the scene.

It was not immediately clear what caused the explosion.