TWO explosive devices have been uncovered in as many days by staff washing potatoes at a frozen food factory.

A worker found a Second World War shell tip among potatoes at McCain's UK head office, in Eastfield, Scarborough, on Friday.

Then came the discovery of a hand grenade from the same period on Saturday at noon.

Police and the Army Logistics Corps were alerted to both incidents and evacuated staff from the premises.

Employees were allowed to return after the Army removed the grenade and carried out a controlled explosion in a field owned by the company.

A McCain's spokesman said that when the company used potatoes from Belgium and northern France, ordinance from the two world wars was sometimes dug up.

But the company denied an Army spokesman's claim that finding the devices was "a fairly common occurrence".

McCain's spokesman said this was the first incident in Scarborough that he knew of, but added that there had been two or three incidents in Whittelsey, near Peterborough, where the assistance of the Army had been requested.

An Army spokesman said: "I can confirm that there was an incident and the disposal team dealt with it."

Ten years ago, a hand-grenade was found in a delivery of potatoes. The discovery was made by staff while they were sorting through potatoes from local farmers. The area was sealed off while a bomb disposal team from Catterick Garrison, North Yorkshire, removed the device.

Then in 2001, soldiers from the garrison once again came to the rescue when staff found a Mills grenade, used by the Home Guard. It was understood to have come from fields in Scarborough.

* Thousands of people were given the all clear to return home yesterday after an unexploded Second World War bomb was made safe. A bomb disposal team started work on Saturday on the 500lb German device, which was dug up on Friday by builders in a garden in Christchurch, Dorset.