Police in Northern Ireland said a device that exploded near the border with the Irish Republic on Monday was designed to lure in and kill officers examining a nearby hoax, raising fears that such incidents could become more common if the U.K. crashes out of the European Union with no deal.

Late on Saturday, police received a report that a suspect device had been left in an area of County Fermanagh, just a few kilometers from the Irish border.

Officers still at the scene on Monday reported an explosion nearby. There were no reports of any injuries, police said.

"While this investigation is at a very early stage, I am of the firm belief this was a deliberate attempt to lure police and the army bomb disposal unit colleagues into the area to murder them," Deputy Chief Constable Stephen Martin said in a statement.

“This attack was indiscriminate and reckless and, whilst there is no doubt in my mind that police responding to this call were the target, the reality is that anyone could have been caught up in the explosion,” he said.

Chief Constable of the Police Service of Northern Ireland, Simon Byrne, called the attack "a sinister development".

The bomb attack in Fermanagh this morning is a sinister development. A clear and deliberate attempt to murder @PoliceServiceNI officers. I strongly condemn these actions and express my sincere thanks to both the Officers and Army personnel for their work in securing the area. https://t.co/ewQDuJ0Dzj — Simon Byrne (@ChiefConPSNI) August 19, 2019

While the 1998 Good Friday deal ended the period in Northern Ireland known as "The Troubles," police officers are still sporadically targeted by small splinter groups of mostly Irish nationalists opposed to Britain's rule over the province.

Last month, police in Northern Ireland said they believed that dissident Republicans tried to kill police officers in the town of Craigavon. In June, police discovered a bomb under a police officer's car in Belfast that they said was probably planted by militant nationalists.

Leaked documents revealed by The Sunday Times newspaper this week suggested that in the event of a no-deal Brexit — where the U.K. leaves with no transition agreement with the European Union — the British government expects the return of a hard border between Northern Ireland, which is part of the U.K., and the Irish Republic, a separate country that will remain part of the E.U., as current plans to avoid widespread checks will prove "unsustainable."

Police on both sides of the open border fear that if checkpoints return they could become a target for militant groups, as was the case in the 1970s.

The mechanics of how to avoid this hard border has become the most contentious part of Brexit negotiations.

Prime Minister Boris Johnson said Britain would leave the E.U. with or without a transition deal on Oct. 31. He has vowed not to pass the withdrawal agreement that his predecessor as prime minister, Theresa May, brokered with the E.U., which includes the so-called backstop — a measure that ensures a soft border between Ireland and Northern Ireland in the event one can't be agreed through a U.K.-E.U. free trade deal.

The border between Northern Ireland and Ireland would become Britain's only land frontier with the E.U.