Firefighters backed by police and soldiers battled for a third day Monday a massive blaze that killed 13 people and ravaged a huge swath of Chile's historic port city of Valparaiso.

It could be yet another two or three days before they succeed in extinguishing the fire, officials warned, the worst to hit the city, consuming 2,000 homes and forcing thousands of people to flee for their lives.

Some people who refused to leave their homes were killed when the inferno swept through.

Hardest hit have been Valparaiso's poorer neighborhoods, perched precariously on the coastal city's tinder-dry hillsides, where dwellings built mostly of wood with tin roofs quickly became engulfed in flames.

Thick smoke has settled over Valparaiso, and ash from the fire rained down on the city's historic port, which so far has been spared the wrath of the blaze.

President Michelle Bachelet has declared the ravaged area a disaster zone, allowing the armed forces to assist in relief efforts and take control of security.

"We are in an ongoing emergency situation," Bachelet's Defense Minister Jorge Burgos told local radio, adding that the fire poses "a very complex situation."

At least 11 helicopters, six planes and 2,000 police and soldiers, in addition to battalions of firefighters, are battling the blaze.

They were heartened by a forecast of cooler temperatures and higher humidity, which was expected to slow the fire's advance.

The city, an architectural gem located about 80 miles (120 kilometers) from the capital city Santiago, is famed for its UNESCO-listed center with cobblestone streets and brightly painted wooden homes.

The fire broke out on Saturday, and whipped up by winds quickly became a fast-moving inferno, so far destroying 850 hectares (2,100 acres) and forcing 10,000 people to evacuate.

'I will not leave'

Some residents -- including a few who later died -- had refused the order to evacuate for fear of losing their possessions to flames or looters, even though police and emergency crews guarded the streets.

"I will not let go of what little I have. This represents 15 years of effort, and until I can no longer see my house, I will not leave it. My wife and my four children are in the shelter," said Arturo Gomez.

About 1,200 people had spent a second night in one of eight shelters that authorities have opened.

Some people who dared to venture back after fire tore through their neighborhoods discovered homes that had been reduced to smoldering ruins.

Health Minister Helia Molina said that in addition to reconstruction, counseling would be offered to those affected.

"We are working with counseling teams to take charge of helping with what it means for a family to lose everything it had, because in this case people lost everything."

The blaze sparked the second mass evacuation in Valparaiso in as many weeks after the city was at the center of a tsunami alert following a magnitude 8.2 earthquake on April 1.

The fire also poses a new challenge for Bachelet, who one month after taking office on a mission to narrow the gap between rich and poor must re-order her priorities.

Bachelet announced she was postponing a visit to Argentina scheduled for Tuesday, in what was to have been her first trip abroad after assuming office for a second term on March 11.

Valparaiso's golden era was from the mid-19th century to the early 20th as a stopover point for ships steaming down South America and to round its southern tip into the Atlantic Ocean.

Fires occur frequently in central Chile, where summer sends temperatures soaring. It is currently autumn in the Southern Hemisphere.

In February 2013, some 105 homes were destroyed in Valparaiso, affecting 1,200 people.