PARIS - One of two mail bombs sent from Yemen last week was defused just 17 minutes before it was set to explode, the French interior minister said on Thursday.

Brice Hortefeux provided no other details in an interview on France's state-run France-2 television, or say where he got the information about the timing.

When investigators pulled the Chicago-bound packages off cargo planes in England and the United Arab Emirates on Friday, they found the bombs wired to cell phones and hidden in the toner cartridges of computer printers.

The communication cards had been removed and the phones could not receive calls, officials said, making it likely the terrorists intended the alarm or timer functions to detonate the bombs, US officials have said. They also that each bomb was attached to a syringe containing lead azide, a chemical initiator that would have detonated PETN explosives packed into each printer cartridge. Both PETN and a syringe were used in the failed bombing last Christmas of a Detroit-bound airliner.

Investigators have centred on the Yemeni Al-Qaeda faction's top bomb maker, who had previously designed a bomb that failed to go off on a crowded US-bound passenger jetliner last Christmas.

This time, authorities believe that master bomb maker Ibrahim al-Asiri packed four times as much explosives into the bombs hidden last week on flights from Yemen. The two bombs contained 300 and 400g of the industrial explosive PETN, according to a German security official, who briefed reporters on Monday in Berlin on condition of anonymity in line with department guidelines.

Bomb 17 mins to exploding