The death toll from a massive wildfire that ripped through Turkey’s mainly Kurdish southeast last week has risen to 15, hospital sources said on Monday as experts pointed to faulty wiring as a possible cause.

The blaze, which broke out on Thursday between the cities of Diyarbakir and Mardin, killed 12 people outright and left five fighting for their lives.

Three succumbed to their injuries on Sunday, the Anadolu state news agency said.

Hospital sources confirmed the toll on Monday, saying two people remained in intensive care.

Hundreds of animals also perished in the blaze that roared across the dry landscape.

The government said “stubble burning” was the cause but the Diyarbakir branch of Chambers of Turkish Architects and Engineers (TMMOB) ruled that out and pointed to faulty electric cables as the likely trigger.

“The fire could have been caused by the power cables,” it said in a report released late on Sunday, indicating there was “no stubble” in the area and saying the electric wires in the area were in a state of disrepair.

“The cause of the fire was not the stubble. The electricity cables and poles were unmaintained and dangerous,” it said, pointing to the absence of “fire prevention measures around the poles”.

The findings came two days after an expert report sent to the local public prosecutor’s office said conductive wire “broke and ignited the grass on the ground and it spread to a wide area due to the effect of strong wind”.

The faulty wiring was on a pole in Koksalan village, in an area where the fields had not yet been harvested, the experts said.

They calculated the blaze had ravaged between 1,650 and 2,000 hectares (4,080 and 4,940 acres) of farmland, forest and residential areas.

Interior Minister Ali Yerlikaya had on Friday blamed the fire on “stubble burning” and the justice ministry said it had opened a probe.

Turkey has suffered 74 wildfires so far this year, which have ravaged 12,910 hectares of land, according to the European Forest Fire Information System (EFFIS).

Experts say human-driven climate change is causing more frequent and more intense wildfires and other natural disasters and have warned Turkey to take measures to tackle the problem.