Bomb de terre: WW1 grenade found in French potato shipment

A German World War I hand grenade was found among a shipment of French potatoes imported for a Hong Kong crisp factory, police said.

The device was safely detonated after it was discovered at the Calbee snacks factory Saturday.

"The grenade was in an unstable condition because it has been previously discharged but failed to detonate," Superintendent Wilfred Wong Ho-hon told reporters.

Police detonated it on site, Wong said, with a police video showing bomb disposal officers packing the grenade in a drainage channel at the factory before blowing it up.

The grenade was eight centimetres (three inches) wide and weighed about one kilogram (two pounds).

"All the information to date suggested that the grenade was imported from France together with the other potatoes," Wong said.

The grenade is believed to have been left in a trench during World War I and accidentally gathered up with potatoes planted a century later in the former battlefield.

"If it was covered in mud, the grenade was likely to have been left behind, dropped by soldiers there during the war, or left there after it was thrown," Hong Kong University military historian Dave Macri told the South China Morning Post.

"The ditch was then filled up and used as a growing field, and the explosive was tossed into the mix of harvested potatoes... and sent to Hong Kong."