Forest fires raging in central Chile have killed at least 46 people, President Gabriel Boric said on Saturday, warning that the death toll is likely to keep rising.

Black smoke billowed into the sky over many parts of the Valparaiso region, home to nearly one million inhabitants in central Chile, while firefighters using helicopters and trucks struggled to quell the flames.

Areas around the coastal tourist city of Vina del Mar have been some of the hardest hit and rescue teams were struggling to reach all the affected areas, Chilean authorities said on Saturday.

President Boric, giving an update to the nation, said 40 people were killed in the fires and another six died from burns in hospitals.

“Given the conditions of the tragedy, the number of victims is sure to increase over the next few hours,” Boric said.

“The situation is really very difficult.”

The death toll means this is the deadliest outbreak of forest fires in Chile in the past decade, Chilean disaster agency Senapred said.

Throughout the country there were 92 active fires, leaving more than 43,000 hectares affected by the incident, Interior Minister Carolina Toha said earlier in the day when she reported 19 dead.

Wildfires are not uncommon in Chile over summer months and last year, on the back of a record heat wave, some 27 people died and more than 400,000 hectares were affected.

“The area with fires today is much smaller than last year (but) at this time the number of hectares affected is multiplying very rapidly,” Interior Minister Carolina Toha said.

Between Friday and Saturday the hectares impacted by the wildfires increased from 30,000 to 43,000.

Toha said that the authorities’ greatest concern was that some of the active fires were developing very close to urban areas “with the very high potential to affect people, homes and facilities”.