A bomb has exploded outside the home of a Northern Ireland police officer in the Culmore area of Londonderry.
The device exploded as Army bomb squad officers moved in to defuse it just after 2pm on Wednesday.
Police said it was fortunate there were no serious injuries or death.
A security alert is underway in the area and the cordon extended following the explosion. Another security alert in Sion Mills in Strabane has now ended and Army technical officers have removed a suspicious object for further examination.
Sycamore Avenue has now reopened to traffic and evacuated residents allowed to return to their homes.
It is understood the Culmore device was planted under the officer's car before it dropped off. It was then spotted by a neighbour.
The device, described as "more intricate" than a basic pipe bomb, exploded as soon as the Army robot touched it.
District Commander Superintendent Gordon McCalmont said the device was designed to kill.
He said: "We should be thankful that we are not talking about the death or serious injury of someone.
"Shortly after 9.30am we were made aware of a suspect device at the home of one of my colleagues in Ardnalee, off the Culmore Road here in the city.
"We immediately took steps to ensure the safety of the community which resulted in 12 families being evacuated from their homes.
"As Army Technical Officers were working on the device, it exploded. My colleague is someone who gets out of his bed every morning to go to work with the sole aim of ensuring the safety of the community and working to prevent harm in the community.
"This is in sharp contrast to individuals who left a viable explosive device in a residential area with kids and families and the dangers don't need to be explained in depth.
"It is our firm belief that violent dissident republicans are responsible for this attack."
The policeman is said to have been badly traumatised.
Superintendent McCalmont continued: "You can imagine the impact on someone who lives and works at the heart of our community and I am sure the trauma for him and his family is quite mammoth."
"This was not a basic pipe bomb but something more intricate but more detail will be provided in time. It was planted there to kill and cause harm and this was an attempt one of my colleagues."
Residents have told the Belfast Telegraph they are angry a police officer living in their community cannot do so in peace.
The Policing Board said the officer involved had a "lucky escape".
The organisation's vice chair Debbie Watters said: “I am grateful that the evil intent of those responsible for leaving this device did not succeed.
"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.
"As a community it is our responsibility to ensure those behind such activity are brought to justice and I would urge anyone with information to bring it to the police or anonymously through Crimestoppers.”
Chairman of the Police Federation for Northern Ireland Mark Lindsay said: "This was a lethal device, capable of killing or maiming the Officer who was targeted, or anyone else who might have come into contact with it.
"This was an act of cowardice. It was reckless and wanton, and displayed utter disregard for life. People who target and attempt to murder Officers have nothing to offer their communities or society at large other than misery and destruction.
"The people who planned and carried out this attack should be ostracised by their own communities and by people who support the democratic path.
"It’s worth remembering that this Officer was singled out because of the job he does, which is to protect the entire community and rid us of this terrorist scourge."
SDLP Leader Colum Eastwood said the "cowards" responsible were "enemies of the Irish people."
"They are enemies of the Irish people. Their malicious and murderous attempt to bring violence back to our streets has failed before and it will fail again.
“My thoughts are with the police officer and their family at what will undoubtedly be a difficult time. No one in this city or in this society should be threatened for the public service they provide.
“If anyone has any information about this attempt to murder a citizen of our city and destroy the hard won peace we enjoy, I would appeal to them to bring it forward.”
The DUP's Gary Middleton condemned those responsible.
He said: “I utterly condemn the irresponsible actions of those who saw fit to leave these devices at the home of a police officer and in Sion Mills. These are despicable acts which endangered the lives of innocent people who simply go about their everyday routine.
"The intentions are to drag Northern Ireland back into the past by instilling fear and intimidation. Our community do not want to see this type of evil activity and this deeply disturbing incident should be unequivocally condemned.
"Republicans will seek to use any political vacuum for their own agenda but they will not succeed. Political stability in Northern Ireland is important. Today we must all stand together to send out a message that it is unacceptable to endanger life in this way and we will continue to work to move Northern Ireland forward.
"As a community there is a duty to ensure this type of activity does not continue and I would urge anyone with information to contact the Police.”