Around a dozen homes were destroyed and five people were hospitalised with breathing problems Saturday in a forest fire near Patras, Greece's third largest city, authorities said.

Some 145 firefighters, 50 trucks, eight firefighting planes and helicopters have been mobilised to extinguish the fire in the Zeria region in the Peloponnese, about 210 kilometres (130 miles) west of Athens, the firefighting service said. 

The authorities evacuated people from five villages in the region as well as from the tourist resort of Loggos on the coast.

Around a dozen homes burned and five people experiencing breathing problems were transported to hospitals in the region, the civil protection authority said.

A motorway in the region was shut down as was the Rio-Antirrio bridge across the Gulf of Corinth connecting the Peloponnese and mainland Greece, the ANA news agency reported, but traffic resumed on  Saturday evening.

Hospitals in Patras and the neighbouring city of Aigio had been put on notice to admit any injured people, while the coastguard have been on standby to rescue any swimmers overcome by smoke.

According to the civil protection agency, 56 forest fires had broken out over the past 24 hours, although most were quickly brought under control.

Greece is hit by forest fires every summer, but experts have warned that global warming increases both their frequency and intensity.

The country has been in the grip of another heat wave since Friday, with temperatures hovering between 42 and 44 degrees Celsius (111 Fahrenheit), weather forecasters say.

Several days ago, a fire ravaged Mount Penteli, close to the capital Athens, but caused no casualties.

It was the same area where a fire in July 2018 went on to claim 102 lives in Greece's worst-ever toll from a forest inferno.