Fire-fighters battle forest blazes in Portugal

More than 700 fire-fighters spent hours last night battling a dozen forest blazes in northern Portugal.



Officials say the cause of the fires has not yet been determined but police are conducting an investigation.



At least three fire-fighters have died in the inferno.

Portuguese police told the CNN that 13 people have been arrested in connection to the fires.



Last year, the Forests National Authority said 20 per cent of Portugal's forest fires resulted from criminal activity while 70 per cent were due to human negligence.