Three police officers escaped injury when their patrol was targeted in an explosive attack.
A device detonated in the Townsend Street area of Strabane, Co Tyrone, on Tuesday night.
While detectives said it was too early to attribute blame, suspicion will again focus on dissident republicans opposed to the peace process.
Police Service of Northern Ireland (PSNI) Chief Inspector Ivor Morton said it was “incredible” that no-one had been killed in the murder bid.
He also declined to be drawn on whether the attack was timed to coincide with the death of former Northern Ireland deputy first minister and ex-IRA commander Martin McGuinness.
“I can’t speculate on what was going through the minds of whoever decided to do this, what I can say is I have no idea what they thought they were going to achieve,” he said.
“It was absolutely utter madness.”
Townsend Street is close to Strabane town centre and adjacent to residential areas.
“It was a deliberate targeted attack on police officers,” said Mr Morton.
“It is incredibly lucky today that I am not talking about the death of police officers or members of the community when you consider where that incident happened and the location and the time of night.”
The chief inspector said the three officers were in “good spirits” despite the experience.
The organisation that represents rank-and-file officers in Northern Ireland, the Police Federation NI, said it was an attempt to murder.
Chairman Mark Lindsay said: “The people who detonated an IED near a police patrol have nothing to offer.
“They are fixed firmly in the past with nothing to offer a community that is trying to build a better here and now and a more positive future.
“They peddle in misery. They are a throwback to bad times.
“They oppress and brutalise people and deserve to be ostracised, caught, convicted and given tough prison sentences.
“Last night, our officers escaped unhurt in a clear attempt to murder and maim.
“On or off duty, officers are at high alert and that situation will remain the case for the foreseeable future.”