SEOUL, South Korea — Wind-driven wildfires that were among South Korea’s worst ever were ravaging the country’s southern regions, killing 18 people, destroying more than 200 structures and forcing 27,000 people to evacuate, officials said Wednesday.

A 1,300-year-old Buddhist temple, houses, factories and vehicles were among the structures destroyed in the wildfires that have burned 43,330 acres and injured 19 people, the government’s emergency response center said.

In a televised address, South Korea’s acting President Han Duck-soo said the wildfires that began last Friday were causing worse damage than many other past wildfires.

“Damages are snowballing,” Han said. “There are concerns that we’ll have wildfire damages that we’ve never experienced, so we have to concentrate all our capabilities to put out the wildfires in the rest of this week.”

Han said crews were struggling to extinguish the wildfires because strong winds swept the areas overnight. Han said about 4,650 firefighters, soldiers and other personnel were working Wednesday to extinguish the wildfires with the help of about 130 helicopters. He said that “a small amount” of 5-10 millimeters of rain was expected Thursday.

Observers say the ongoing wildfires are the third biggest in South Korea in terms of land burned.

Officials in several southeastern cities and towns had ordered residents to evacuate Tuesday as firefighters struggled to contain multiple blazes fueled by dry winds. The largest fires were in Andong, the neighboring counties of Uiseong and Sancheong, and the city of Ulsan, according to South Korea’s Interior Ministry.

Earlier on Tuesday, officials had said firefighters had extinguished most of the flames from the largest wildfires in those areas, but wind and dry conditions allowed the blazes to spread again. But efforts to fight the fires were partially suspended overnight as the winds strengthened.

The blaze in Uiseong destroyed Gounsa, a temple built in the 7th century, according to officials from the Korea Heritage Service. Some of the temple’s treasures, including a stone Buddha statue, were evacuated before the fire reached the wooden buildings.

The Korea Forest Service said it had raised its wildfire warning to the highest “serious” level nationwide Tuesday, requiring local governments to assign more workers to emergency response, tighten entry restrictions for forests and parks, and recommend that military units withhold live-fire exercises.

The 18 dead include four firefighters and government workers who were killed in Sancheong on Saturday after being trapped by fast-moving flames driven by strong winds, according to officials.

Government officials suspect human error was the cause of several of the fires, possibly due to the use of fire while clearing overgrown grass in family tombs or sparks from welding work.