Earlier, specialist mountain rescue teams joined a police helicopter and a coastguard helicopter based in Sligo in the search.
As well as a reported a sighting, several local people have said they heard a loud bang in the area at around 10am.
The search operation has been declared a major incident by police, who have brought in support units form outside the area to join local officers and local firefighters in the search.
The search was over a wide area from Enniskillen northwards to Belleek and from Lower Lough Erne westwards to the border.
