A man who discovered a pipe bomb outside his family home carried the lethal device to a field so it would not explode near crowds of children.
Sean McGeough said the bomb was left inside a bag at the front door of his mother's home in Dunmurry, on the outskirts of west Belfast. He discovered the device in the Teeling Avenue area at around 7.30am yesterday.
When he realised what it was he ran with it to a nearby field so that it would not detonate close to where schoolchildren were waiting for their bus.
Prominent republican James McCormick, who was acquitted of involvement in the murder of Robert McCartney, lives in the area.
It is not known if he was the target of the attack, which was last night being blamed on dissident republicans.
"I'm not speculating about what this was about but we are very annoyed about it," Mr McGeough said.
"My mum was asleep in bed when I found it. We were very lucky it didn't go off. My grandmother lives just a few houses away too."
The 27-year-old added: "I looked in the bag and it was a bomb with nails. There were young kids going for buses so I grabbed the bag and ran with it to a field then phoned the police.
"It took them an hour and 15 minutes to turn up. Although they sent the helicopter quickly.
"My mum is very shaken up. I mean, her son ran down the street with a viable device in his hand.
"We're going to have to review our personal security now."
The device was declared viable by police after a controlled explosion was carried out by army bomb squad officers.
SDLP councillor Brian Heading said large numbers of people were unable to go to work or access emergency services because of the security alert.
"The Mount Eagles estate is to the left and there are 600 homes there, for example," he said.
"Because of the way the roads are in the area there is only one way to go up to Lagmore Avenue.
"Police and ambulance and fire services would have been effectively excluded at the time. People weren't able to get into town to work, deliveries to the shop were prevented."
Sinn Fein councillor David Bell said: "People have been telling me that they must have passed this device on the way out in the morning, so it's a miracle no-one has been injured. This has to be totally and utterly condemned as an attack on the community."