It was about an hour before dawn on Sunday morning when the group of armed gang members, clad in black, arrived in a dead-end street in Manurewa.
They approached a home towards the end of Oratu Pl, where inside three men and their nan lay asleep in their beds.
According to a relative of the men who lived nearby, and another neighbour familiar with the events, the group of Black Power members numbered between 10 and 20.
The witnesses, who spoke on condition of anonymity, said the attack was retaliation for an incident that happened a few days earlier. They would not be drawn on the nature of the incident.
The relative of the victims said the group held down his uncle, gave him a beating then shot him in both thighs with a .22 calibre rifle. His cousin was shot in the shin and was less badly injured than his uncle, who was bleeding profusely.
The men shot at him four or five times as he clambered over a fence to escape but he was not hit. The relative said he had picked up several .22 shell casings.
The relative said he felt sick when he went into the house and saw his uncle, who had been shot in the thighs, bleeding profusely.
He said his uncle repeatedly asked for a glass of water while he was covered in blood waiting for emergency services to arrive.
Another relative of the victims said the nan who lived at the property, and who was shaken but unhurt, was much loved by the family and doted on her mokopuna.
A neighbour said he heard at least six gunshots.
He went outside to see the attackers clad in black in the driveway pursuing and shooting at the man who managed to escape over the fence.
The neighbour said he feared he could have been shot amid the mayhem.
Late on Sunday morning, police were still arriving in force at the property. Armed officers were stationed outside, the driveway was cordoned off and forensic specialists were donning boiler suits.
There has been no word of any arrests.
A police spokeswoman confirmed they were investigating two people who received gunshot wounds in the incident, reported about 4.30am, but provided no further information.
Another neighbour described the attack as cowardly. He said he had experienced no end of trouble since moving into the street a couple of months ago. There were frequent visitors to the home where the shooting happened, the neighbour said.