From Northport to Mapleton, wildfires crackled across the state Monday, prompting the Maine Forest Service to repeat its pleas for caution by homeowners eager to clear land despite extremely dry conditions.

The service said 90 such fires have been reported since April 29.

Three fires Monday caused special concern to rangers:

. A fire in Township 24, between Route 9 and Columbia Falls, in Washington County had burned 12 acres by Monday afternoon.

. An estimated 25 acres were burning in coastal Northport.

. In Mapleton, firefighters were called to the west side of Hanson Lake where a 3-acre fire was reported late Monday afternoon.

A state helicopter from Old Town and several area fire departments were called to assist in fighting the Mapleton fire.

Rangers were still investigating what caused the three fires.

On Sunday, 10 wildfires broke out in Maine, according to Jim Downie of the Maine Forest Service.

The largest Sunday was in Masardis, where 25 acres of grass and forest burned. Downie said children were the likely cause of that fire.

Rangers and firefighters also worked Sunday to extinguish a fire in Addison that claimed 500 acres after a firefighting effort that began Friday. The Addison fire, near Big Ridge off Route 187, at one point during the weekend was consuming 100 acres an hour, Downie said.

Downie said Monday that investigators think they know where that fire began, but noted that the fire is not believed to have been of suspicious origin.

Meanwhile on Monday, an incinerator fire at a River Road home in Cushing spread to a small field and into nearby woods, burning about three-quarters of an acre.

The owner of the home, Bob Doyle, did not have a burn permit, Cushing Fire Chief Arthur Kiskila said, noting that the incinerator being used also did not comply with burn permit rules for that type of fire, such as having a screen over the top of the barrel and keeping a specified distance around the barrel free of flammable material.

Monday was a Class 4 fire day, Kiskila said, which means that there is a “very high” risk of forest fire. Class 5, the highest rating means that there is an “extreme” chance of a forest fire.

And a forest ranger confirmed Monday that a three-alarm fire in the woods off Beechwood Street in Thomaston last Wednesday was started by children.