Inspector Dawson said: "Officers were in a building in the Ravenhill Reach Court area responding to an unrelated report, when a suspected gas leak was detected in a communal area around 9.15pm.
"The building was evacuated and a nearby community centre was opened for residents while colleagues from the Northern Ireland Ambulance Service and Northern Ireland Fire & Rescue Service attended the scene.
"It has since been established that this was not a gas leak and at this time, we believe that some kind of noxious substance was released inside the building.
"Residents were able to return to their homes around 11.40pm and enquiries are ongoing to establish the source of the substance.
“Two other police officers were also affected, but did not require hospital treatment. A number of residents were also displaying symptoms.
"I would commend the professionalism of the officers who were in attendance. Despite suffering from the effects of the substance, they ensured that residents were evacuated to safety.
"If anyone has any information, please contact police on 101, quoting reference 1423 of 22/9/23."
Alternatively, you can submit a report online using our non-emergency reporting form via http://www.psni.police.uk/makeareport/
You can also contact Crimestoppers anonymously on 0800 555 111 or online at http://crimestoppers-uk.org/