THE worst forest fires to hit Greece in a decade have claimed the lives of at least 20 people near Athens as they attempted to flee the flames in cars or on foot.

A spokesman for the Greek government confirmed the rising death toll.

At least 69 other people have been hospitalised with injuries. Many are in serious condition. Greece has sought international assistance to cope with the fires near the capital, which have destroyed dozens of homes, burned cars and prompted tourists and Greeks 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.

Two major forest fires are burning out of control on either side of Greece’s capital, burning houses, prompting residents to flee and turning the sky over Athens a hazy orange from the smoke.

Greece’s coast guard says a search-and-rescue operation is underway for several people, believed to be foreign tourists, who fled a massive forest fire in a boat and were missing.

A coast guard helicopter and vessel were searching the sea near the town of Rafina, northeast of the Greek capital of Athens. They acted after receiving notification from Danish authorities, who had received a call from someone in Greece saying they were among a group of 10 people who fled a forest fire in a boat.

The coast guard said it was unclear what type of vessel the 10 people were in.

Regional Greek authorities have declared a state of emergency in the eastern and western parts of greater Athens, as fires fanned by gale-force winds raged through pine forests and seaside towns on either side of the Greek capital. Greece is seeking assistance from the European Union to battle the fires.

In nearby Mati, the coast guard was sending a patrol boat to evacuate people trapped on a beach by the flames.

The blaze has created such thick smoke that the main highways between the Peloponnese and the Greek mainland have been shut down and an orange haze has descended on Athens.

The first fire broke out in a pine forest near the seaside settlement of Kineta 50km west of Athens between the capital and Corinth. At least 150 firefighters were on the scene while five water-dropping planes and seven helicopters helped to fight the blaze from the air.

The second major fire broke out Monday afternoon in the Penteli area northeast of Athens. Local authorities said they were evacuating children’s summer camps, while dozens of homes and cars were destroyed. At least three aircraft and a helicopter were battling the flames, along with at least 50 firefighters.