The blaze in the southern Algarve resort province, located 250 kilometres (150 miles) south of Lisbon, surrounded the hillside town of Marmelete and forced 300 people to flee their homes, the director of the National Rescue Operation Centre, Gil Martins, said.

"The fire is moving quickly and it is burning with intensity," he told a news conference.

Some 170 firefighters equiped with nearly 50 vehicles and five water-dropping aircraft, including a Canadair plane which arrived from Spain on Sunday in response to a plea for help from Lisbon, were battling the fire.

More firefighters were expected to arrive on the scene later on Sunday, Martins said.

Firefighters said winds in the area were changing direction frequently and this was making it difficult to put out the fire.

"There are houses burning in the area, people are in a panic," the town priest told the Lusa news agency.

A religious festival which was due to take place in Marmelete was canceled because of the blaze, Lusa reported.

The agency said local residents were instead handing out the food intended for the celebration to exhausted firefighters.

The Algarve receives the bulk of Portugal's summertime visitors and had so far escaped damage from wildfires which have swept through the country since the end of July, killing 15 people and causing nearly one billion eurosbillion dollars) in damage.

Firefighters, aided by cooler overnight temperatures and higher air moisture levels, had gained the upper hand in their battle against the fires over the weekend, but by late Sunday afternoon a number of smaller blazes grew in intensity as winds picked up speed.

Martins said firefighters were on the scene of eight other fires, including a stubborn blaze near the central town of Portalegre which has burned for two days.

Roughly 200,000 hectares (494,000 acres) of woodland have been lost to flames so far this year, most of it since July, a forest service estimate released on Friday said.

But forestry experts, who have studied satellite images of the fire damage, told daily newspaper Publico on Sunday the total burnt area is likely to be at least 300,000 hectares.

The European Union has said it will offer financial aid to help Portugal, one of its poorest members, cope with the disaster.

Police meanwhile arrested one more suspected arsonist on Sunday as part of their investigation into the wildfires, bringing the total number of arrests in recent weeks to 53.

Authorities suspect 30 percent of the fires were deliberately set.

TERRA.WIRE