Vandals in Germany have destroyed two experimental sites growing genetically modified (GM) wheat and potatoes.

On the night of 9 July, half a dozen masked attackers overpowered the security guard watching over test fields in Gross Lüsewitz, near Rostock, reported Science Now.

They then destroyed a field of wheat resistant to fungal diseases and a field of potatoes engineered to produce cyanophycin, an amino acid polymer that could potentially be used to make plastics.

The fields were part of a trial funded by the German government to develop a more-efficient testing system for gm crops. Two nights later, a dozen attackers threatened guards with pepper spray and bats at a demonstration garden in Üplingen, in the state of Saxony-Anhalt.

They destroyed a field of potatoes and trampled wheat and maize. Police estimate the damages from the attacks at more than €250,000. No suspects have been arrested.