Independent traders are demanding a fresh crackdown on the effects of legal highs in Exeter city centre.
Business owners on Fore Street say levels of criminal and antisocial behaviour from drug users in the area have risen sharply in recent weeks.
Some of the alleged activity – ranging from verbal abuse to smashed windows – is being blamed on customers of a legal high store.
Problems have apparently increased since another legal highs shop, Wicked, on South Street was closed by police on November 3 following complaints about anti-social behaviour by customers.
Mattie Richardson, owner of Bunyip Beads and Buttons, said: "These problems are happening day-in day-out, and they are having a detrimental effect on business. If the behaviour is not dealt with, the situation will only get worse and worse."
Shopkeepers have reported damage to their property as well as a surge in nuisance and disorder related to drugs.
Lewis Macskimming, of Otto retro antique sellers, said: "In the past few weeks it's been horrendous. My windows were kicked-in, and we've been shoplifted. People have tried to sell me stolen goods, and we've seen people openly dealing drugs. The day-to-day abuse on the street is terrible.
"It's a perfect storm for drug takers, because lots of people want to help those begging for money and nobody has been able to get a competent grip of the problem.
"Exeter is starting to become a beautiful and trendy city. But its progress is being strangled by this humungous problem."
Business owners claim the antisocial behaviour is affecting their trade, because customers are being "frightened" and "intimidated" on the street.
Hayley and Nathan Maker, of No Guts and No Glory, said: "It's very unpleasant when we have customers in the shop, and there are drug deals or fights happening outside."
David O'Callaghan, of Gentry hair salon, said: "These people are frightening my customers away and causing my business a lot of grief. I saw one guy with four or five packets in his hand and he could barely stand-up straight."
Vicki Parks, of Hidden Treasure Tea Room, said: "The guys that were taking heroin are now taking legal highs because they are cheaper and more readily available. The line between what is legal and illegal is blurred."
Vicki is facing a £3,500 bill after the shop's three large front windows were keyed.
She added: "They haven't just done it once; they've done it on every single pane."
Police Sergeant Rob Bolt said: "We are fully aware of the current situation regarding antisocial behaviour, including the transfer of problems from South Street to Fore Street.
"We are monitoring the street through increased patrols and use of CCTV, and we are gathering evidence to establish what is causing the behaviour.
"We have given out appropriate warnings, and if there is sufficient evidence we will consider using antisocial behaviour legislation."
