At least 49 people have died and more than 150 others, including 16 children, have been injured as forest fires in Greece rage near the capital of Athens.

According to the Greek Red Cross, 26 bodies were found in the yard of a villa in the seaside village of Mati, which is at the centre of the disaster.

Red Cross chief Nikos Economopoulos reportedly said some of the bodies found were locked in embrace.

Before that news, the official death toll stood at 24.

The Greek coast guard said four bodies have been found at sea near the wildfires raging near Greece’s capital.

Two major fires are burning out of control on either side of Greece’s capital and a government spokesman Dimitris Tzanakopoulos told the Associated Press that at least 69 people had been taken to hospital with serious injuries.

Greece has sought international assistance to cope with the fires, which have destroyed dozens of homes, burned cars and prompted residents and tourists to flee to beaches east of Athens for dramatic rescues by boats.

Prime Minister Alexis Tsipras cut short a visit to Bosnia on Monday and returned to Athens to preside over an emergency response meeting with fire chiefs and government officials.

Wiitnesses told Reuters they saw at least four dead on a road in the community of Mati, about 29 kilometres east of Athens, with the popular tourist destination devastated by the fast-moving blaze that broke out on Monday evening.

One victim was in a car, while another was beneath a vehicle.

Two people died on a motorbike in what appeared to be a traffic queue heading to a nearby beach.

There were several reports of missing persons, including four tourists from Denmark.

Other journalists said they counted at least seven dead on a road in Mati.

Hundreds of people have been urged to evacuate affected areas. Photo: Getty

One local TV channel said eight bodies were being transferred by boat to the port of Rafina, near Mati.

As the fire raged and darkness fell, the extent of the disaster was impossible to gauge.

“We are dealing with something completely asymmetric,” Mr Tsipras said.

Greek authorities have urged residents of a coastal region west of Athens to abandon their homes as a wildfire burned ferociously, closing one of Greece’s busiest motorways, halting train links and sending plumes of smoke over the capital.

Many residents escaped to nearby beaches for evacuation by boat. Photo: Getty

Bushfires are not uncommon in Greece, but a relatively dry winter created tinder box conditions. It was not clear what ignited the present  fires.

The army was drafted in on Monday afternoon to help fight the blazes.

Achilleas Tzouvaras, a senior fire chief, went on state TV to appeal to people to leave the area of Kineta west of Athens after some tried to stay on their properties.

“People should leave, close up their homes and just leave,” he said.

“People cannot tolerate so much smoke for so many hours. This is an extreme situation.”

-with AAP