A pipe bomb has been found in Newtownabbey amid reports that it had been thrown at a police patrol.
A security alert in the Mill Road area began shortly after 10pm last night following a telephone call stating that a device had been aimed at police.
A subsequent search located two suspicious objects at around 12.30am, prompting a road closure and the evacuation of a number of homes.
Army technical officers declared one of the items a hoax but said the other was a viable pipe bomb-type device.
PSNI Chief Inspector Stephen Reid, Area Commander of Newtownabbey and Carrickfergus, said: "This device was clearly designed to kill police officers and we are very fortunate no-one was killed or injured.
"Had it exploded it could have killed or maimed anyone close by, police officers or local people alike.
"Those responsible showed total disregard for the local community and put the lives of local people in the area at risk.
"I would like to thank to local residents for their patience and support throughout this operation and I want to reassure them that we will not be deterred by this attack."
Mill Road was reopened to traffic and residents allowed to return to their homes shortly before 5am.
Officers have appealed for anyone with information about the incident to come forward.