It is the fourth parcel bomb in recent months blamed on the blackmailer, who has demanded 10 million euros (RM48 million) worth of bitcoins from the parcel delivery service DHL.

The latest parcel containing explosive material was sent to the Berlin Chamber of Crafts and “can in all likelihood be attributed to the DHL extortionist or extortionists,” a Potsdam police spokesman said.

A female employee at the trade association contacted the police on Thursday after she noticed wires protruding from the package.

Specialists were able to defuse the parcel without having to carry out a controlled explosion.

German police have been hunting for one or more suspects ever since a DHL parcel containing nails, screws, and explosive powder from Polish fireworks, was received by a pharmacy in the city of Potsdam, near Berlin, in December.

That package failed to detonate upon opening but nevertheless prompted police to clear the nearby Christmas market as a precaution.

The evacuation revived fears of the jihadist attack on a Berlin Christmas market attack a year earlier, which killed 12 people.

Police later discovered a message inside the package threatening further parcel bombs unless DHL made a 10 million-euro (RM48 million) untraceable payment in bitcoins.

A similar package was sent to an online retailer in the eastern city of Frankfurt (Oder) in November, believed to have come from the same source.

Another parcel bomb linked to the extortion plot was delivered to a Berlin bank in January, containing a detonator and what appeared to be powder from fireworks. It was also defused by police.