It's believed two recent gorse fires in south Donegal may have been started deliberately.
A major cross border operation ensued on Sunday evening last to reports of a fire near Belleek.
Another similar fire also happened near Pettigo.
Now the Northern Ireland Fire service have confirmed that they believe that they may have been started deliberately.
An investigation is continuing.
Local Sinn Fein Cllr Michael McMahon says it's a very serious matter that could have been worse had it not been for the swift response of the emergency services: