Costas Karamanlis, the Greek prime minister, said: "So many fires breaking out simultaneously in so many parts of the country cannot be a coincidence."
"The state will do everything it can to find those responsible and punish them."
Two youths were also arrested on suspicion of arson in the northern Greek city of Kavala, said Nikos Diamandis, a fire department spokesman.
The fire department said 26 villages had been evacuated across the country by the end of Saturday.
Fires reached the edge of the capital, Athens, and ashes rained down on the Acropolis.
On the nearby island of Evia, hundreds of people, including tourists were evacuated from their hotels.
Hospitals on alert
Diamandis said 70 new fires had broken out on Saturday, while dozens still burned from the day before.
Volunteers with garden hoses and buckets joined firefighters in the battle to save lives and homes.
An extra 500 soldiers will join firefighters on Sunday, the fire department said.
At least 12 countries also pledged reinforcements, including firefighting aircraft and crews.
Many of the deaths occurred near the town of Zaharo in Greece's southwestern Peloponnese region, with firefighters searching through charred houses on Saturday.
Laurence Lee, Al Jazeera's correspondent in Zaharo, said: "The people here feel powerless. There is nothing they can do but sit and watch."
Charred bodies were found in "cars, houses and in fields" in the area surrounding Zaharo.
"It's a Biblical catastrophe, the sight is horrible. I saw people burnt alive in their cars," Christos Kafiras, the prefect of the Ilia fire department, told a television channel on Friday.
Hospitals across Greece were on alert, and the health ministry sent tents for 1,500 people to the south to shelter those made homeless by the flames.
Pantazis Chronopoulos, the mayor of Zaharo said he feared more people could be dead.
"We still have missing [people] who haven't been found. We have about 10 missing," he said, adding that soldiers had begun checking burned houses for more possible victims.
Nicole Itano, a journalist in Athens, told Al Jazeera: "There is a lot of suspicion that these fires and previous fires from the summer have been set by arsonists.
|Charred bodies were discovered in cars by |
"The suspicion is that people are setting fires in order to clear land for new developments.
"People here are simply stunned by the sheer number of the fires."
Itano said that gale force winds had made it difficult for firefighters.
She said that "even without those winds I think firefighters would have been hard pressed to deal with them simply because there are so many".
Itano also said that the government had come under criticism for not being prepared despite "knowing this was going to be a long, hot, dry summer".
"The mood in Greece is definitely one of anger and this may affect the ruling party as they go into elections," she said.
Greece is expecting to hold early elections in September.