A 38-year-old man assisting in the blaze in the north of Athens has died after being seriously injured in the fire-stricken area, as devastating fires continued to spread across the country.

The man was transferred to hospital with serious head injuries after being hit by a falling electricity pole but did not make it, the local KAT hospital said in an announcement.

At least 44 people were transferred to hospitals from the fires in Attica, Peloponnese and Evia with burns, breathing problems and slight injuries, Health Minister Vassilis Kikilias said on Friday.

Greek Deputy Minister for Civil Protection and Crisis Management Nikos Hardalias said earlier in an emergency briefing that there were 56 active fire fronts in different parts of the country, stressing that the conditions were "extremely dangerous."

Fires continued to rage across the country for the fourth day on Friday in northern Athens, on Evia island, in Ilia prefecture and Mani in Peloponnese, forcing hundreds of people to evacuate their homes, destroying houses, businesses and burning thousands of hectares of forest land.

Foreign officials from France, Spain, Kuwait, Jordan, Turkey, the United States and China, among other countries around the world, have sent messages of solidarity to Greece.

"We express our support to the Greek people who are being tested by the extreme temperatures and devastating wildfires," the Chinese embassy in Greece said in a tweet, sharing their admiration towards the firemen, army forces and volunteers.