Crews continued their search for hot spots in the East End wildfires Monday, with forest rangers sifting through the scorched Pine Barrens.

Forest rangers from the Department of Environmental Conservation (DEC) have been working to locate any lingering hot spots beneath the soil. As they dug through the charred earth, they checked for any signs of heat to ensure that no flames were left smoldering beneath the surface.

“You’ll see a little bit of smoke or you’ll smell a little bit of smoke, and then you really have to dig it up and expose it to figure out where the heat’s coming from,” said John Gagne, a forest ranger with the DEC.

Meanwhile, Suffolk County officials have released new information about the likely cause of the fires — and it appears the initial spark came from a rather unusual source.

According to Suffolk Police Commissioner Kevin Catalina, the fires started when someone in Manorville was cooking s'mores at around 9:30 a.m. Saturday.

The embers from the backyard fire were carried by strong winds on Saturday, spreading flames to other areas including Eastport, East Moriches and Westhampton.

“All of those fires are in a direct line with the strong northwest wind that was blowing that day, and it is believed that the embers from each fire traveled and continuously started more fires,” said Catalina.

Some local residents expressed disbelief at the cause.

“It’s a little sad that a nice family event went a little sideways,” said one resident.

“I’m surprised it was s’mores, yeah. It’s very unusual," said another resident.

Forest rangers reported that they had successfully extinguished at least seven hot spots Monday within the boundaries of the Westhampton fire.