An explosive device was fired at police in Northern Ireland but failed to hit its target, officers said last night.

Members of the public in Newtownbutler, Co Fermanagh, have been placed on high alert following a telephone warning that the device was lying on wasteground near the town.

Dissident republicans in Fermanagh and elsewhere have been blamed for bomb and gun attacks on police in recent times and senior officers have said the threat remains grave.

Chief Superintendent Michael Skuce said: "Calling police two days later and failing to provide any useful details as to the location of the device demonstrates the indifference and disregard these people have for anyone but themselves and their own selfish motives.

"Causing disruption and distress to ordinary decent people at this time of year, when people are preparing and looking forward to Christmas, is despicable."

Mr Skuce said leaving such a potentially deadly device on open ground where anybody could come into contact with it was totally irresponsible, particularly considering that the school Christmas holidays started today.

"I would like to make a direct call to those involved to provide more specific information as to the location of this device," he added.

"Let's not bring misery and destruction to anyone's door this Christmas. Let your conscience speak louder than your prejudices."

Officers are conducting an operation and are appealing for anyone with any information to come forward.

People in the Newtownbutler area are also being warned that, if they come across something suspicious or out of place, not to touch it, but to contact their local police station immediately.

Earlier this year, Police Service of Northern Ireland (PSNI) Chief Constable Sir Hugh Orde said his officers were taking longer to respond to emergency calls because of the danger from renegade republicans opposed to the Northern Ireland peace process.

There have been mortar and gun attacks in Counties Fermanagh, Londonderry, Tyrone and Armagh.

Last month the body which monitors the activity of armed groups, the Independent Monitoring Commission (IMC), warned that republican dissidents were more active than at any time in the last four and a half years.

In its 20th report, the IMC said dissidents engineered public disorder to expose officers to attack.

It said the current political vacuum in Northern Ireland is likely being exploited by the groups.

In its report to the British and Irish Governments, the IMC said dissidents had sought to raise tensions with loyalists during the parades season.

Assembly member Tom Elliott said: "This is reckless in the extreme.

"This is very worrying indeed and I must stress that this type of republican activity or behaviour must not be tolerated in Fermanagh, or anywhere throughout Northern Ireland."