A forest fire that broke out in the southernmost region of Portugal four days ago continued to rage on Tuesday, with more than 1,000 firefighters battling the flames, according to authorities.

The fire was "extremely active" overnight due to strong winds that fanned its flames, regional Civil Protection commander Luís Vraz Pinto told the press.

As well as affecting the regions of Monchique, Odemira and Silves, the blaze had also started to encroach on the Algarve's port city of Portimão.

Members of the National Authority for Civil Protection (ANPC) and Republican National Guard evacuated over 250 people overnight from various villages located in mountainous terrain.

Some 29 people have been lightly injured, one seriously, out of a total of 79 people who have received assistance.

The blaze was concentrated in six hot spots across two areas: near the town of Casais and near the swamp area of Oldelouca, Vraz Pinto said.

Portugal's secretary of state for Civil Protection, Artur Neves, said the primary goal was to "safeguard all the people."

Some 1,203 firefighters, 375 land vehicles and 19 firefighting aircraft were battling the inferno.

Weather forecasts were not favorable for the extinguishing efforts, with temperatures expected to exceed 35 degrees Celsius (95 degrees Fahrenheit) as well as wind.