“We want to get hold of the results of the probes into the other attacks to compare them with ours and to see if it could be the same attacker or group,” public prosecutor Lorenz Hase told AFP.

He confirmed reports that a man wearing a baseball cap and large sunglasses seen running out of the Ikea store immediately after Friday’s explosion spoke English. He was confronted by an Ikea employee but allowed to go.

The explosion on Friday evening in the kitchen equipment department of the furniture store left two customers needing hospital treatment for blast trauma, reports said.

On May 30, small explosives concealed in alarm clocks detonated at Ikea furniture stores in the Belgian city of Ghent, Lille in northern France and Eindhoven in The Netherlands, causing no damage or injuries.

No one has claimed responsibility.

Ikea spokeswoman Camilla Meiby told AFP Sunday that Ikea was aware German investigators were probing a possible link, but that the firm had no other comment for now.

She added that the Swedish chain, which generates annual sales of some €23 billion ($33 billion) and operates in 41 countries, had not hiked security measures.

“We always have very high security and safety so there is nothing extra. We are just keeping the very high standard that we always have,” Meiby said.