Cameron wrote in the News of the World, Britain's biggest selling Sunday newspaper, that the bomb "bears the hallmarks of Al-Qaeda".
In Dubai police said the bomb found there contained the high explosive PETN -- the same substance used by the would-be 2009 Christmas Day "underpants" bomber Farouk Abdulmutallab and 2001 attempted shoe-bomber Richard Reid.
Dubai police chief General Dahi Khalfan told AFP: "This was a parcel bomb and a terrorist act could have occurred," adding that the device could have "exploded" on board the airplane had it not been intercepted in time.
The device consisted of a computer printer whose ink contained explosive material, connected to a mobile phone SIM card and a circuit board, a police statement said.
The statement said it "bears the hallmarks of those used by terrorist organisations like Al-Qaeda."
So, those hallmarks of 'Al Qaeda' in full:
1. Being the kind of thing a terrorist does (e.g. a bomb)
2. Including a standard kind of high-explosive