Dissident republicans tried to murder the parents and a sister of a police officer yesterday.
Nobody was injured but a vehicle damaged after a device exploded outside his mother and father's home in Londonderry early yesterday morning.
The officer's sister's house was targeted in a separate incident in the city yesterday morning, but the pipe bomb was made safe. He is back on duty and has vowed he will not be intimidated.
Both attacks were claimed by the Real IRA.
Chief Superintendent Stephen Martin said: "This is an officer who joined the service to make a difference, to serve the community, to work to make the city in which he was brought up safer.
"Contrast his courage and his bravery in putting the uniform on and joining the service with the cowards who hid in the shadows and planted these under cars and scurried off to their beds."
The explosion happened in the Drumleck Drive area of Shantallow, a mainly nationalist estate in Derry's Cityside, at around 1.30am today. The car was taken away for forensic examination.
It is understood the targets were a man and his wife, well respected locally. She prayed dissident republicans would see the error of their ways in the Catholic church the day before she was attacked, local people said.
Mr Martin added: "Had anybody been close to that device when it exploded they could have been killed or seriously injured."
In the incident at the policeman's sister's home at Kylemore Park a pipe bomb was discovered. It was viable and a controlled explosion was carried out.
Mr Martin said it was spotted at around 7.30am. He added his police colleague was determined to face down the assailants.
"While he is concerned and worried about his family he is also resolute that he will not be deflected by this," he said.
It is understood the policeman worked for a spell in New Zealand and is currently a physical education instructor within the force.
Mr Martin appealed for members of the community to come forward to help catch those responsible.
Separately, a man was shot in the legs and hand today in a paramilitary-style attack by the Real IRA.
The victim was hit a number of times in both legs and the left hand and is in a stable condition in hospital after treatment.
Police said a number of men forced their way into a house in the Ballymagroarty area of Derry shortly after 1.30am and shot the man.
Security Minister Paul Goggins said: "No one should be under any illusion of the motives behind those who, under the cover of darkness, leave devices outside family homes.
"They are a threat to the local community, they want to inflict pain and suffering on the people living in that community and do not care who they kill or injure. These latest attacks are beyond contempt."
Policing Board chairman Barry Gilligan said it was a vile and cowardly attack.
There is no place in our society for anyone who carries out such violent attacks," he said.
"This police officer has chosen to do a job serving the community and this is an attempt to intimidate him and his family within that community."
Sinn Fein Assembly member Raymond McCartney condemned the attacks.
"This family is a part of our community and I would call on the community to show solidarity with them at this time," he said.
"While most people are working to build a peaceful and democratic future, it would seem that a minuscule and unrepresentative group think that by carrying out cowardly actions based on spurious excuses, they will frustrate continued progress."
MP Mark Durkan said: "These are cowardly and sinister attempts not only to unnerve a young officer and his family but to intimidate the entire community."