Updated

A forest fire that engulfed a hill in the Chilean port city of Valparaiso destroyed at least 70 homes and forced the evacuation of more than 500 families, officials said on Thursday.

Chile's emergency office, ONEMI, issued a red alert after the blaze broke out on the city's San Roque hill, some 75 miles (120 kilometers) northeast of the capital, Santiago.

Strong, changing winds and high temperatures at the peak of the Southern Hemisphere's summer holiday season stoked the fire. Valparaiso Regional Gov. Raul Celis called it "the city's worst blaze in two decades."

Local television stations aired images of a towering plume of smoke billowing over Valparaiso. The smoke kept firefighting aircraft grounded while more than a dozen firefighter units, 700 policemen and several army platoons continued to battle the fire five hours after it started.

Twenty-seven people, including five children, are being treated for minor injuries and smoke intoxication, said Claudio Fernandez, director of the local Van Buren Hospital.

Police said they had arrested at least three people for looting.

The port of Valparaiso is surrounded by dozens of hills where most people live. Authorities say the fire is centered near the hills in the highest part of Valparaiso, and is still far away from the city's low-lying downtown area.

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Associated Press Writer Luis Andres Henao contributed to this report.