Police have warned of the dangers of fentanyl which has been cut into batches of heroin over recent months and have contributed to some local drug-related deaths.

Of the 135 people who died as a result of drug misuse in Norfolk between 2015 and 2017, 45 were in Norwich, data from the Office for National Statistics, released last week, reveal.

It means the city continues to see one of the highest rates of deaths from illegal drugs in the country.

At a rate of 12 deaths in every million, the only towns nationwide with a higher rate are Swansea, Port Talbot and Hartlepool.

Chief Inspector Sonia Humphreys, of Norwich county policing command, said: 'Deaths as a result of fentanyl nationally are rising and continue to rise. It has been since 2016 that we have been starting to see a rise in deaths. What we were finding is about 12 or 18 months ago, they found a fentanyl factory up north. Sometimes a grain of this stuff in a heroin sample can be toxic enough to kill people.

'Adding things to these drugs we weren't expecting is causing some of these deaths. We have had a couple of deaths around that locally.'

Since November 2016 Norfolk Police have been targeting Class A drug dealing in the county under Operation Gravity. Around 670 arrests have been made in that time.

'We continue to target Class A distributors in the city,' added Chief Insp Humphreys. 'We appreciate there are vulnerable people in the city and when you look at homelessness, we often find drug misuse falls within that.

'People use drugs for a whole host of reasons. The data that has come out isn't just around drug misuse at Class A levels. Some is using them for suicide purposes, and notes females are more likely to be doing that.

'We have got our mental health nurses in our control room so there is early assistance and support for people who need mental health services.

'We want to make it as hostile as possible for suppliers coming into the city. Wherever you have got demand for something you are going to have suppliers. There is a big part to play for our partners to reduce that demand, but we need to be concentrating on the suppliers.'

Anyone with information about illegal drugs in their area should call Norfolk Police on 101.