The explosions are believed to have been attempts at blackmail.
"Both detained men are 39 years old. One of them, who plotted the crime, Adam K., is well-educated, worked in corporations. The other, Mikolaj G., had been linked to drug crimes in the past," Poland's RMF commercial radio reported.
Contacted by AFP Friday, Polish police confirmed they were "taking action in connection with the case", but refused to give further details about the investigation.
According to RMF, police were also looking for a third suspect - likely the bomb maker - and had confiscated evidence including laptops and mobile phones.
Booby-trapped alarm clocks blew up at Ikea stores in Belgium, France and the Netherlands on May 30, while a blast in the kitchen equipment department of a store in Dresden, Germany, reportedly left two customers needing hospital treatment on June 10.
On September 2, police evacuated two stores in the Czech Republic defusing
a booby-trapped device found near one of them.