The largest ever UK seizure of synthetic opioids has been made by police and border officials in a series of raids that also saw 11 arrests. Around 150,000 tablets of a drug called Nitazene were found in Waltham Forest, east London, in a factory set up to make the pills, police said. Detectives believe the drug was being sold on the dark web. They also found various other class A and B drugs, a gun, a pill pressing machine, more than £60,000 in cash and £8,000 in cryptocurrency stored on hard drives. A series of raids were carried out in Waltham Forest and Enfield, north London, on October 24, with 11 people arrested between August 21 and November 21 and all charged with conspiracy to supply class A and B drugs. British law enforcement are aiming to stop any rise in the use of synthetic opioids amid a decrease in heroin being smuggled from Afghanistan. They want to avoid a situation similar to that in the US, where the number of fatal fentanyl overdoses went up by three times in the five years to 2021. Detective Superintendent Helen Rance, leading the investigation, said: “Synthetic opioids have been detected in batches of heroin found in London and across the UK; they substantially raise the risk of incredibly serious harm to the user and are believed to be linked to a number of deaths. “We are working closely with partners to monitor and proactively tackle this issue, provide advice and remove the availability of these dangerous drugs from our streets.” Police say anyone who has taken synthetic opioids should get medical treatment urgently. They have taken the unusual step of highlighting signs that someone may have taken one of these drugs, including: having small, narrowed pupils; reduced or loss of consciousness; dizziness or drowsiness; difficulty breathing; nausea or vomiting; cold or clammy skim; blue or grey lips and fingernails; low blood pressure or decreased heart rate. Ms Rance added: “The public health advice remains that illegal drugs should not be consumed. There are support services available for people who need help. Anyone who has consumed synthetic opioids and experiences the symptoms described should seek urgent medical treatment.”