(Updates death toll, adds details of fire fighting effort, color)
By Anthony Esposito
VALPARAISO, Chile, April 13 (Reuters) - At least 11 people were killed and 500 houses destroyed over the weekend by a fire that ripped through parts of Chilean port city Valparaiso, as authorities evacuated thousands and used aircraft to battle the blaze.
Pushed by strong Pacific coast winds, the fire rampaged over 700 hectares (1,729 acres) of forest and hilly residential neighborhoods including La Cruz and Las Canas, local authorities said.
Some 1,200 firefighters were battling the blaze, using three planes and four helicopters to drop water on the flames.
The fire started on Saturday, with most of its damage done overnight. At daybreak on Sunday, Valparaiso was a stench-filled scene of smoke, ash and sirens as residents picked through the remains of their homes and firefighters struggled to put out active points of the blaze that stubbornly remained.
"It is still not completely extinguished," said local government official Ricardo Bravo.
Weather forecasts called for high temperatures and strong winds on Sunday afternoon, a combination that could exacerbate the disaster if the remaining flames were not put out in time.
"We fled from the La Cruz neighborhood, from an apartment I just got not too long ago. It's all burned down, my sister's house also burnt to the ground," said a visibly upset Rosa Guzman as she stared helplessly up at the hills.
The country's Congress, which is housed in Valparaiso, and the city's historic quarter, with its late 19th century architecture, were spared by the blaze.
There were no reports that exports of copper in the world's No.1 producer of the metal were affected by the fire.
President Michelle Bachelet declared a state of emergency and sent the army in to maintain order. Marines patrolled the streets while ambulance crews treated people for smoke inhalation and other injuries.
This is the second emergency that Bachelet has had to face in the first month of her new term after an 8.2 earthquake slammed northern Chile at the start of April. (Writing by Hugh Bronstein; Editing by Sandra Maler)