16 February 2013 Last updated at 06:29 ET

Reward offered after seven Lincoln shop robberies

A £3,000 reward is being offered to help catch armed robbers who have raided seven shops in Lincolnshire.

Police said the robbers have used knives to threaten staff in the raids over the past six weeks in Lincoln.

In one raid, the robbers used what appeared to be a gun to rob a food store on the Ermine estate in Lincoln, police said.

The charity Crimestoppers is offering the reward for information leading to a conviction in any of the cases.

Crimestoppers spokeswoman Sue Langley said: "I am appalled at this spate of robberies that has hit Lincoln in recent weeks and it makes me angry that innocent people running their businesses are being targeted."