The attack happened on Lisnahull Road shortly after 11am, with emergency services responding to reports of an incident inside a home.
The man was found at the property and was pronounced dead at the scene. A young girl was also seriously injured and is receiving medical care.
A woman is believed to have suffered injuries as well.
Police have arrested a teenage male in connection with the incident. He remains in custody as investigators examine the circumstances that led to the man's death and the injuries sustained by the other victims.
The alarm was reportedly raised by a neighbour who heard a woman inside the property screaming for assistance. Emergency services subsequently attended the scene.
Police have established a cordon around the house as specialist forensic teams conduct examinations. Investigators are expected to continue gathering evidence and speaking with people who may have information about what occurred.
The incident has had a significant impact on the local area. Deirdre Varsani, a local Sinn Féin councillor, said there was a palpable feeling of disbelief among residents.
She expressed sympathy for those directly affected, as well as anyone who witnessed the events or has been impacted by what happened.
Councillor Varsani said the community would need to deal with the consequences of the incident in the days and weeks ahead, as residents come to terms with what has happened.
The investigation remains ongoing.
