Portugal on Wednesday appealed to EU partners for assistance in fighting a wildfire on the Atlantic island of Madeira that has raged for a week and threatened a UNESCO-listed forest.

The country will shortly trigger the EU Civil Protection Mechanism to bolster firefighting efforts with two Canadair water bomber planes, a government source told the Lusa news agency.

The head of the regional government, Miguel Albuquerque, said 60 extra firefighters and first aid specialists had arrived from the Portuguese mainland on top of 76 already sent since the wildfire started on Wednesday last week.

The fire had burned 4,392 hectares (10,850 acres) of land up to Tuesday, the European Union's Copernicus observatory said on the X social media platform. It added that more than 950 hectares had burned in the previous 24 hours.

Regional civil protection chief Antonio Nunes told RTP public television that the flames had touched a part of the Laurissilva forest, the largest surviving laurel forest, that is on UNESCO's World Heritage List. He said the damage was not significant.

More than 100 firefighters battled the blaze on two main fronts on the island which is traditionally packed with summer tourists at this time, the civil protection service said in a statement.

Fierce winds that have fuelled the flames have also disrupted operations at the island's main airport at Funchal. But its management said the site was working normally this week.

The fire started in the Ribeira Brava district and spread to the nearby Camara de Lobos and Ponta do Sol districts in the southern part of the island.

About 200 people were evacuated from their homes to avoid smoke inhalation, but most have since returned.

Authorities said no house had been destroyed, nor any injury reported, but some firefighters had symptoms of exhaustion.

Thousands of hectares of vegetation were lost in a wildfire last year and at least three people were killed in a 2016 wildfire near the main city of Funchal.