PARIS — French authorities have ferried firefighters and trucks from the mainland to Corsica to help battle a forest fire that has been raging for three days.

The regional authority for southern Corsica warned Friday that the fire has spread north and it could take several days to extinguish the blaze on the Mediterranean island.

Some 70 new firefighters and 15 vehicles were sent Friday from the mainland, but the regional authority said rough terrain and exceptionally hot, dry weather is complicating efforts.

The fire broke out Wednesday in the Palneca forest, forced evacuations on a celebrated hiking route and threatened nearby towns at the height of vacation season. No one has been hurt.

Fires in recent days have also threatened a seaside town south of Athens in Greece, and in southern Albania.