Increased security is in place at Middlemore Hospital in south Auckland where the victims of two shootings and a beating were treated at the weekend.
The hospital says it has stepped up security in the short term because staff are worried about their own security.
Brad Healey, general manager of medicine at Counties Manukau DHB, says it has put significant stress on staff who were left wondering when the next serious incident was going to arise.
Mr Healey says the additional guard is a temporary arrangement and the hospital will review its security arrangements next week.
The weekend's events include a man, 26, who was shot three times outside his home in Papatoetoe about 12.20am on Sunday. Two of the wounds were to his head.
Detective Inspector John Tims says it appears the victim knew his killer, but the motive for the attack is not known.
Police are looking for the driver of a black sportscar seen leaving the area. He is described as a male Maori aged about 30, 1.7m tall, with short hair.
In the other cases, a teenager, 15, was shot in the leg in Mangere at 9.30pm on Saturday.
Another man, 19, from Papakura is in Middlemore Hospital with head injuries after being found on a netball court. Police have been told of a fight in the area about 2am on Sunday. His condition is described as critical.
Police say the pieces are coming together as they hunt the perpetrators.