No damage or injuries were caused by the explosion in Lille, nor by those in the Belgian city of Ghent or Eindhoven in the Netherlands.
"The information we have is that the explosions happened the same way in all locations, with booby-trapped alarm clocks that had been hidden exploding," An Schoonjans, spokeswoman for Ghent prosecutors, told AFP.
In Ghent, an employee and a security agent complained of ear aches after two small explosions, which detonated almost simultaneously before the store closed Monday evening.
Two booby-trapped alarm clocks were detonated by remote control, Schoonjans said.
The spokeswoman said the circumstances were similar in Eindhoven and Lille, but she was unable to provide details.
"We are in contact with judicial authorities in Eindhoven and Lille to see if there is a link between the three affairs," she said.
Belgian police were to inspect the country's six Ikea stores.