A Taser stun gun has been used on a 19-year-old who was arrested by police in north Belfast.
The PSNI said the youth had tried to attack officers and ignored police warnings before he was fired at.
The teenager, who was examined in hospital, was later detained in connection with an altercation and assault early today.
A PSNI spokeswoman said police were called to a disturbance in the Manor Street area of the city before 3am and separated a number of youths who had been fighting.
"During the altercation an attempt was made to assault police, a warning was given and ignored, and a Taser unit was discharged by a specialist firearms officer," she said. "The man was arrested and is currently assisting police with their enquiries."
The Police Ombudsman of Northern Ireland has been informed in line with agreed PSNI protocols.
Two other men, aged 19 and 20, were slightly injured during the altercation.
Tasers were first issued to a team of specially trained firearms officers in Northern Ireland at the start of last year. Police maintain they are only used by officers across the UK and Ireland as an appropriate and proportionate option to bring dynamic situations under control.