Terry Spence, chairman of officers' representative body the Police Federation, said the device was planted by "cowardly thugs":
This was an attempt to murder an off-duty police officer.
But this attack is no great surprise. Scores of police officers have been forced from their homes in the last 12 months because of terrorist incidents. This is just the latest of many.
It reinforces the need for officers to be extra vigilant.
More top news
After the heatwave come the storms, with lightning flashes illuminating the night sky across much of the country last night.
An Independence Day event at a UK base has been cancelled by the US Air Force over security fears.
British firms predict the economy should sustain a "solid" pace of growth for the rest of the year thanks to lower oil prices and inflation.