The incident took place on Tuesday afternoon, on what was one of the windiest days of the year so far which no doubt would have hampered fire-fighter’s efforts to fight the flames.
Vast plumes of thick black smoke could be seen for most of the afternoon from as far away as neighbouring county Lagoa.
The National Authority for Civil Protection (ANPC) told The Portugal News that 32 vehicles and 95 fire-fighters from ten different corporations were dispatched to the locale to tackle the blaze. Also present at the scene were a number of local dignitaries and GNR officers.
It took fire-fighters over four hours to dominate the flames, having reached the spot at around 3.50pm, reporting the fire was under control at 8.20pm and extinguishing it a short while later. Two bulldozers were sent in from Silves and Lagos to clear tracks.
No one was injured in the fire and no material damage was caused.
Investigating GNR officers identified a 78-year-old Portuguese man who is suspected of being the culprit through negligence.
It is thought the pensioner started a fire on a plot of agricultural land to clear it, but failed to contain the flames.
The man has been formally identified by police and declared an official suspect.
Controlled fires, or queimadas, to clear agricultural land and renew pastures, are generally permitted at this time of year but only if the necessary steps have been taken beforehand.
According to the INCF (Institute for Nature and Forest Conservation) a special licence is required from the local Town or Parish Hall, issued with the say-so of a specialised technician or firemen.
Failure to comply with the rules and regulations of queimadas can result in fines of between €140 and €60,000, and should it originate a forest fire, criminal charges as foreseen by law 56/2011 can also apply.