Hamburg (dpa / lno) - During exploratory work in the Hamburg warehouse district, an old German anti-aircraft shell was found in the water.

Immediately afterwards, the grenade was towed under water in a transport box to the less densely populated Magdeburg harbor, which is only a few hundred meters away, and blown up there in the Elbe, said a fire department spokesman in Hamburg on Thursday.

No buildings had to be evacuated.

The grenade was 8.8 centimeters in diameter. This world war ammunition was quite explosive because of its adjustable time fuse, the spokesman said. "The fact that the adjustment device no longer works reliably is what makes it so dangerous." The grenade was found around 11 a.m. on Thursday and had already been blown up in the afternoon. The "Hamburger Abendblatt" had previously reported.