The shooting of an off-duty policeman was a "despicable and horrendous act", a senior detective has said.
A burned-out car was found a short time later
The 43-year-old Catholic had just left his son off at a school in Bishop Street, Londonderry, at about 0830 GMT.
He was able to drive himself to a police station, and his injuries are not thought to be life-threatening.
Dissident republicans are suspected of being responsible. Deputy Chief Constable Paul Leighton said "violence like this has no place in our society".
It is understood the officer is from the mainly-Catholic Bogside area of Derry - during the Troubles, many Catholics in Northern Ireland were reluctant to join the police but reforms have seen increasing numbers signing up in recent years.
DCC Leighton said: "I know this officer and he joined the Police Service of Northern Ireland to serve every section of the community."
He added: "It's absolutely abhorrent that a public servant going about his daily business can be attacked in this way."
Sinn Fein's Martin McGuinness condemned the attack, saying those responsible "have no popular support and have no strategy to achieve a united Ireland".
A shotgun was fired into his car, and he was struck by a number of pellets on his face and an arm.
A car believed to have been used in the attack was found burned-out in the Creggan area of the city at 0900 GMT.
The scene has been cordoned off, and the injured officer was taken to Altnagelvin Hospital for treatment.
Local priest Father Roland Colhoun said it was "horrendous" for such an attack to happen outside a school.
There has been widespread condemnation of the shooting
"Anyone would assume that a man is entitled to leave his child to school in safety, to leave the child there, and to go home and to be well enough in the evening to come back and collect the child," he said.
Northern Ireland Secretary Shaun Woodward said: "There can be no greater contrast between this police officer serving his community and the criminals who attacked him."
DUP First Minister Ian Paisley described the attack as "the bottom level of hatred and bitterness", adding that dissident republicans were "getting angry because they are making no headway".
SDLP leader Mark Durkan said: "It is important not only that the policeman knows that the whole community stands behind him, but that those responsible for this attack know that they do not have support from the community."