A number of PSNI officers were also taken to hospital as a precaution, the PSNI have said.
Several streets in the Holylands have been sealed off as emergency services deal with the ongoing incident.
Police, ambulance and the Fire Service were tasked to Damascus Street in the student area shortly before 5.30pm on Tuesday.
Around 30 firefighters, including a specialist hazardous materials unit, were at the scene but have since ceased operations.
District Commander, Superintendent Allister Hagan said: “Our priority is always the safety of the public and our officers.
“While a number of people were taken to hospital as a precaution, I want to reassure the community that this incident is contained and there is no risk to the wider public. We continue to work with partner agencies to confirm the circumstances and will provide updates as appropriate.”
The NI Ambulance Service (NIAS) said they received a number of 999 calls at around 5pm and despatched four emergency crews to the scene.
Emergency services at the scene of serious ongoing incident in the Damuscus Street – Holylands area of south Belfast on September 30th 2025 (Photo by Kevin Scott)
Four hospitalised after serious incident in south Belfast
An NIAS spokesman confirmed four patients have been taken to Royal Victoria Hospital after initial treatment.
A PSNI spokesman said several people are receiving medical treatment in hospital with their conditions deemed not life-threatening.
“Police alongside colleagues from other emergency services are at the Damascus Street area of south Belfast after a number of people became unwell this evening, Tuesday 30th September,” the spokesman added.
“A number of people have been transported to hospital for treatment. Members of the public are advised to avoid the area at this time. A further update will be provided in due course.”
Several streets were sealed off as a precaution with residents of Damascus Street advised to close their windows and doors.
Emergency services at the scene of serious ongoing incident in the Holylands area of south Belfast on September 30th 2025 (Photo by Kevin Scott)
Two search and rescue teams, three ambulances and six police cars were deployed to the scene.
At least four fire appliances attended the incident, including crews from Central, Cadogan, Lisburn and Dromore stations.
The Belfast Telegraph understands that one person was put in hand and leg restraints at the scene.