Thousands of people fled their homes north of Athens on Tuesday as a wildfire broke out in the forest and reached residential areas. The precipitous evacuations came as Greece struggled with its worst heat wave in decades.

The fire sent a huge cloud of smoke over Athens and caused multiple evacuations near Tatoi, 20 km (12 1/2 miles) to the north. Residents left their homes by car and motorbike, heading for the capital amid a blanket of smoke.

“It’s a big fire and it will take a lot of work to bring it under control,” Greater Athens Regional Governor George Patoulis told ERT state television. “The foliage is very dense in these areas and it is very dry due to the heatwave, so the conditions are difficult. “

As the flames approached their homes, residents were seen running towards their cars, their faces covered in wet rags to protect them from the thick smoke. A group stopped to help staff at a riding school push their horses into trucks to escape the flames.

As the scorching heat wave in the eastern Mediterranean intensified, temperatures reached 42 degrees Celsius (107.6 Fahrenheit) in parts of the Greek capital. Extreme weather conditions fueled deadly forest fires in Turkey and fires in Italy, Greece, Albania and across the region.

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Forest fires have also raged in other parts of Greece, prompting evacuations in a coastal area in the southern Peloponnese as well as on the islands of Euboea and Kos, authorities said.

The fires prompted Greek basketball star Giannis Antetokounmpo to cancel planned celebrations in Athens for the NBA championship he recently won with the Milwaukee Bucks.

“We hope there will be no casualties from these fires, and of course we will postpone today’s celebration,” Antetokounmpo wrote in a tweet.

Earlier, authorities closed the Acropolis and other ancient sites during the afternoon. The site, which is normally open in the summer from 8 a.m. to 8 p.m., will have reduced hours until Friday, closing between 12 p.m. and 5 p.m.

The extreme heat, described by authorities as the worst in Greece since 1987, has strained the national power supply and fueled forest fires.

Five dropped planes and five helicopters were involved in fighting the fire near Athens, including a Beriev Be-200 amphibious aircraft leased from Russia.

The blaze damaged power pylons, adding further strain to the already pressurized power grid due to the widespread use of air conditioning.

The Greek fire services maintained an alert for most of the country on Tuesday and Wednesday, while public services and some private services changed their hours of operation to allow for afternoon closures.