They have confirmed the bomb found consisted of 60kg of homemade explosives contained in a beer keg.
Army Technical Officers carried out a clearance operation on the suspicious car and the viable device was made safe.
In a statement issued by the PSNI today, District Commander Pauline Shields said the lives of residents had been "put at risk by an element intent on causing loss of life and disruption. "
"The people responsible for this have no regard for the lives of anyone in our community. It is fortunate that no one was killed or seriously injured as a result of this reckless act," she said.
It's understood up to 20 families were evacuated from their homes during the security operation, which has now ended.
"The people who carried out this act are not part of the society within which the majority of people of Northern Ireland wish to live," said the senior officer, "The subsequent complex operation has tied up resources that would otherwise be dealing with community issues."
Detectives now want to hear from anyone who may have travelled along the Derrylin to Enniskillen Road late on the evening of Thursday 21st March into the early hours of Friday 22nd March.
Police are keen to hear from anyone ho saw any suspicious persons or vehicles including a silver Volkswagen Bora car.
Detectives can be contacted at Enniskillen on 0845 600 8000. Information can also be given anonymously to Crimestoppers on 0800 555 111.
Lisnaskea police station is adjacent to Lisnaskea High School and opposite a residential area.
Fermanagh and South Tyrone MLA Tom Elliott has condemned those responsible for the bomb and blamed dissident republicans.
"This could have been disastrous," he added.
DUP MLA Arlene Foster has said there "would have been carnage" had the bomb been detonated. She praised the security forces for defusing the viable device, as did her party colleague, Jeffery Donaldson.
Sinn Fein's Phil Flanagan said those behind bomb should "desist from such activities that recklessly and needlessly put lives in danger.".
In a frank tweet from the Police Federation of Northern Ireland, a spokesperson wrote: "These cowardly thugs still don't get it. Terrorism will never succeed."