Children playing in a park in Strabane could have been killed by a large pipebomb which lay unexploded nearby, police have warned.
The device was thrown early on Thursday morning, but wasn't found until that evening - between the perimeter fence of the local police station and a play area in Coutrai Park.
A phone call had been made to police telling them it hadn't exploded.
"This was a large device which, had it exploded, could have killed or maimed anyone in the vicinity," local PSNI Area Commander, Chief Inspector Andy Lemon, said.
"Two controlled explosions were carried out on Thursday night - the device was so large that parts of the device landed within the station perimeter."
One man who'd been at the play park earlier that day, with his two young children, said he was furious they had been put at risk.
"This is another example of the cowardly element in our society who show no regard for our local residents or police force," Chief Inspector Lemon added.
"With the warm weather and school holidays, the park is becoming busier and it does not bear thinking about what could have happened - had a child at the park discovered the device before anyone became aware of the potential danger."
Residents were told to stay indoors during the alert.
Local Sinn Féin councillor Jay McCauley said such an attack on a police station was "futile" and condemned the danger posed to the community.
"Rather than putting their energies into causing disruption for the local community, those involved should recognise the absolute futility of their actions," he said.
"They should join with the overwhelming majority of people in this area who are trying to forge a better future for this community and in turn to adopt a constructive strategy towards achieving the objectives Irish republicanism."