Neighbours have spoken of their shock after a 19-year-old woman was rushed to hospital with wounds to her chest following a stabbing near Lisburn in County Antrim.
Three other people also suffered injuries in what police are describing as a domestic incident.
Police later fired a Taser at a man who was carrying two knives in the kitchen of a house in Lambeg early yesterday morning.
The woman's injuries, while serious, are not believed to be life-threatening.
A 21-year-old man was arrested on suspicion of attempted murder after the incident at Woodland Avenue.
Two men aged 24 and 46 and a 48-year-old woman were also treated for injuries sustained as a result of the incident. They have since been released from hospital.
It's not clear what the relationship is between the injured woman and the attacker, and none of those injured in the incident has been named
Neighbours spoke of their shock at the incident in what they said was a normally quiet street.
They said they hoped the injured woman made a full and speedy recovery.
A PSNI spokeswoman said: "Police responded to a report of a domestic incident in the Woodland Avenue area shortly after 2am this morning after it was reported that a woman had been stabbed.
"Upon police arrival a male, carrying two knives, was observed in the kitchen of the property struggling with a woman.
"Specialist firearms officers entered the property and spoke with the male.
"In order to prevent harm to the male himself or anyone else, a Taser was discharged by one of the specialist firearms officers."
In line with police protocols as the Taser was fired, the Police Ombudsman was informed of the incident by the PSNI." There appeared to be no one at home at the Woodland Avenue property yesterday afternoon.
One resident, who didn't wish to be named, said he heard some of what went on.
He said: "I saw three police Land Rovers and a marked police car and an unmarked police car and ambulances flying down the road and they were there for a long period of time.
"I heard a male voice shouting 'It's serious, where is the ambulance?' Police were there at that time and the first ambulance appeared very shortly after that.
"I saw the guys with baseball caps and I thought that looked like armed response, and they carry Tasers," the man said.
Neighbour Clare Lewsley (69) said: "This is shocking and I hope the woman will be OK. I never heard a thing last night because I was asleep at the back of the house, but normally I would hear a dog bark or anything.
"I am very shocked and I hope the woman is OK. We don't want to hear anything like this happening."
Lisburn Alliance councillor Brian Dornan said the speed of the police response had to be commended.
Reacting to reports that the incident was domestic in nature, Mr Dornan, who is a member of the policing partnership in Lisburn, said police there have been focusing on the issue.
He said: "The police are very proactive in Lisburn with domestic incidents. I can't comment on the specifics of this incident but police have been concentrating on domestic incidents and part-fund a special Women's Aid worker in Lisburn police station, who works closely with frontline officers."
A Police Ombudsman's report in 2012 found that in the first 20 investigations completed into the use of Tasers here, the police acted within guidelines.
Investigators also found that in most incidents the officers said they used it to prevent members of the public from harming themselves. There have been no deaths in Northern Ireland so far following Taser use.