Two men have been arrested in relation to the supply of a 'lethal high' after police received almost 40 reports of people falling unwell in two days.
On Sunday, Northumbria Police received 12 reports in just three-and-a-half hours of people falling unwell after taking what is believed to be either 'Spice' or 'Power'.
In total 17 reports were received throughout the day.
Five people were taken to hospital as a precaution but were all released a short time later.
An investigation was launched into who had supplied the drugs and a warning was issued to the public on Sunday about the dangers posed by 'lethal highs' or NPS.
However, since the weekend there has been a further 20 reports of people falling unwell.
Only one person was taken to hospital as a precaution before he was later discharged.
An investigation is being led by a team of detectives with the support of Newcastle's City Centre Neighbourhood Policing Team and two people have been arrested in connection with the supply of the substances.
A 19-year-old men has been released under investigation but officers have charged a 29-year-old man for possession of a controlled class B drug with intent to supply.
Superintendent Paul Knox, of Central Area Command, said: "We can confirm that we have had nearly 40 reports of people heavily under the influence of lethal highs in Newcastle in just three days which is a worryingly high number.
"None of the six individuals taken to hospital have fallen seriously unwell and other users have not required any medical treatment. Nevertheless, people need to understand the dangers of these substances.
"Lethal highs put people into a zombified state - they become lethargic, slow to respond and are sometimes completely unresponsive.
"We have received calls of genuine concern for these people but many of them don't want to comply with police or our partners.
"We will do all we can to offer them support but these incidents put a considerable strain on the emergency services who are responding to calls to people being found slumped on pavements and park benches.
"These types of reports are being seen across the country in our major cities and we would reiterate that Newcastle doesn't have more of a problem than other cities.
"Our main priority is public safety and we want to take lethal highs off our streets once and for all.
"Two people have been arrested in light of these most recent reports and there are already more than a dozen individuals going through the court system on similar offences connected to the supply of lethal highs.
"We will do all we can to work with the local authority, public health and the ambulance service to refer users to the relevant support networks. However, we will not back down in our proactive policing approach so we can put those who are taking advantage of vulnerable people before the courts."
Councillor Nick Kemp, Cabinet Member for Neighbourhoods and Regulatory Services, said: "This spike in reported incidents of lethal highs is very worrying.
"It demonstrates that despite legislation banning them they are still in circulation and we must continue to be vigilant and report their use because they really do destroy lives and destroy our communities.
"I commend Northumbria Police for their proactive approach to this problem and want to be clear that the council will continue its fight against the possession and supply of these dangerous substances."
The substances in question were formerly known as a 'legal highs' but new legislation was introduced in December to criminalise the drugs.
They are now referred to as either New Psychoactive Substances (NPS) or 'lethal highs'.
In 2016 Northumbria Police set up a dedicated task force in Newcastle to crack down on the use of NPS in the city and over the past 18 months they have been working with Newcastle city council, North East Ambulance Service and Public Health.
That work has seen them seize hundreds of thousands of pounds worth of the drug and, when the drugs were still legal, saw a number of shops that stocked the dangerous substances shut down.
Investigations into the supply of lethal highs and other illegal substances across the force area are ongoing and anyone with any information on lethal highs can get in touch with police on 101.
Anyone who needs advice on drugs should contact FRANK on 08700 77 6600 or visit www.talktofrank.com. You can also contact local charity Lifeline on (0191) 2614719 or by visiting http://www.lifeline.org.uk/