SANTIAGO, CHILE — Firefighters wrestled Sunday with massive forest fires that broke out in central Chile two days earlier, as officials extended curfews in cities most heavily affected by the blazes and said at least 64 people were killed.

The fires have been burning with the highest intensity around the city of Viña del Mar, where a famous botanical garden founded in 1931 was destroyed by the flames on Sunday. At least 1,600 people were left without homes.

Several neighborhoods on the eastern edge of Viña del Mar have been devoured by flames and smoke, trapping some people in their homes. Officials said 200 people have been reported missing in Viña del Mar and the surrounding area. The city of 300,000 people is a popular beach resort and also hosts a famous music festival during the southern hemisphere’s summer.

Rodrigo Mundaca, the governor of the Valparaiso region, said Sunday that he believed some of the fires could have been intentionally caused, replicating a theory that had also been mentioned on Saturday by President Gabriel Boric.

“These fires began in four points that lit up simultaneously,” Mundaca said. “As authorities we will have to work rigorously to find who is responsible.”

The fires around Viña del Mar began in mountainous forested areas that are hard to reach. But they have moved into densely populated neighborhoods on the city’s periphery despite efforts by Chilean authorities to slow down the flames.

On Saturday President Gabriel Boric said that unusually high temperatures, low humidity and high wind speeds were making it difficult to control the wildlfires in central Chile, which have already burnt through 8,000 hectares of forests and urban areas.

Officials are asking people in areas affected by the fires to evacuate their homes as quickly as possible, while those further from the fires are being told to stay at home in order to facilitate the transit of fire engines and ambulances.

Curfews have been declared in Viña del Mar, and the neighboring cities of Quilpé and Villa Alemana as part of an effort to prevent looting.

The fires broke out during a week of record high temperatures in central Chile. Over the past two months, the El Niño weather pattern has caused droughts and high temperatures in western South America that have also increased the risk of forest fires.