Six people have been killed in Portugal as the country was hit by a record number of forest fires, and three more have died in Spain where blazes sparked by arsonists have been fanned by strong winds from Hurricane Ophelia. In Portugal, Prime Minister Antonio Costa announced a state of public calamity, as 3,700 firefighters battled 26 major fires stretching across the centre and north of the country. The deaths, confirmed by Portugal's national civil protection agency, came four months after 64 people were killed and more than 250 injured on June 17, in the deadliest fire in the country's history. In addition to the six dead, some 25 people had been injured, civil protection agency spokeswoman Patricia Gaspar said, with three motorways, including one linking Lisbon and Porto, closed. The recent fires have been caused by "higher than average temperatures for the season and the cumulative effect of drought, which has been felt since the start of the year", she said. In Spain, authorities were blaming arson for some 17 fires which have caused three deaths. "They are absolutely intentional fires, premeditated, caused by people who know what they are doing," the head of the regional government, Alberto Nunez Feijoo, said. Fifteen separate wildfires which posed a risk to built up areas were raging across the region of Galicia, he said. The flames were being fanned by wind gusts of up to 90 kilometres per hour as Hurricane Ophelia moved north off the coast of Spain towards Ireland, he told private broadcaster La Sexta. "The situation is critical," he said. Feijoo said "thousands" of firefighters, soldiers and locals were battling the blazes. "We have not had a situation like this in the past decade. We have never deployed so many means at this time of the year," he said. Prime Minister Mariano Rajoy, who is from Galicia, expressed his condolences to the victims in a Twitter message. Five wildfires were raging near Vigo, Galicia's biggest city, forcing the evacuation of a shopping mall and a PSA Peugeot Citroen factory on the outskirts of the city. The flames had reached O Castro, a large hilltop park in the heart of Vigo with sweeping views of the city's estuary, Spanish public television station TVE reported. Images broadcast on Spanish TV showed local residents, their mouths and noses covered with handkerchiefs, battling the flames with buckets and pans of water. The city of around 300,000 residents has opened up two sports centres and booked rooms in three hotels for people who were forced to evacuate their homes.