A man in his thirties has been shot in the leg in an attack which police said "has all the hallmarks of a paramilitary-style shooting".
Three masked men were involved in the attack in the Magowan Park area of Creggan, Londonderry, on Wednesday, the Police Service of Northern Ireland said.
Detective Sergeant McLaughlin said the incident took place at around 11pm and was "completely unacceptable".
He added: "This has all the hallmarks of a paramilitary-style shooting.
"It was a planned, vicious and brutal attack, which is completely unacceptable in today's society."
The victim has been taken to hospital for treatment and anyone with information is asked to call police on 101 or Crimestoppers anonymously on 0800 555111.
Sinn Fein MLA Karen Mullan condemned the shooting.
"There is no place for attacks like this in our society and those responsible are not representative of the local community," she said.
"This comes at a time when our medical staff are under intense pressure and the community is dealing with the biggest public health crisis it has ever faced.
"Whoever did this needs to listen to the people of the area and end these attacks immediately."