A booby trap bomb believed to have fallen from a police officer's car in the North has exploded as Army disposal experts were approaching it.
No-one was injured when the device detonated in the driveway of the officer's home at Ardanlee in the Culmore area of Derry.
It is understood the bomb was lying on the driveway, having fallen off the policeman's vehicle as he drove away from home on Wednesday.
The finger of blame will again point at dissident republicans opposed to the peace process.
A Police Service of Northern Ireland (PSNI) spokeswoman said: "We can confirm that the device exploded as ATO (Army Technical Officers) were in the process of making it safe."
Vice chairwoman of Northern Ireland's Policing Board Debbie Watters said the officer had a "very lucky escape".
"I am grateful that the evil intent of those responsible for leaving this device did not succeed," she said.
"This officer has had a very lucky escape but such activity reinforces the continuing threat that exists for our police officers both on and off duty."
The Northern Ireland Police Federation, the body that represents rank and file officers, called for the people who carried out such attacks to be "ostracised".
A spokesman said: "Once again we see police officers targeted for simply trying to protect the community.
"The people who are intent on targeting and attempting to murder police officers have nothing to offer their community or society at large other than misery and destruction.
"These people should be ostracised by all people who support the democratic path."
Several homes have been evacuated in the area following the discovery of the bomb.
The Minister for Foreign Affairs and Trade, Charlie Flanagan TD said: "I was shocked and appalled to hear that a bomb exploded on a street in Derry today and has now forced twelve families to leave their homes tonight.
"This was a reckless and criminal attack, which put an entire street in danger. There is no excuse, no justification, for such irresponsible criminality."