Concern as boy, 13, is sold knife in Derby
A 13-year-old boy has been sold a knife during a series of test purchases in Derby.
The initiative also saw seven out of 26 shops fail alcohol test purchases and four out of 23 fail on cigarette sales.
The city council said these results, from between June and September, showed how important it was to closely monitor age-restricted sales.
Officials added they would carry out further operations having received funds for another 64 test purchases.
Matthew Holmes, deputy leader of Derby City Council, said underage sales were putting young people at risk.
"It has a big impact on health and contributes significantly to many other problems as well.
"While underage sales of knives are very low, one sale is still too many, especially as it was made to a 13-year-old boy," he said.
Action was still being considered against the stores involved.