“This morning [Saturday] four more suspects were arrested, bringing the total to six,” said Lt-Col Andrè Traut.
Anne Marks, 59, was shot and killed on Friday during a shootout between two groups believed to be in gangs, Traut said.
“During the same incident, three children aged six, 14 and 16 were wounded and admitted to hospital. They too were caught in the crossfire,” he said.
He said Ebrahim Daniels, 18, died in hospital due to injuries he sustained after the shooting on Friday night.
“Two charges of murder and two of attempted murder are being investigated.”
After the incident, three men were arrested and an unlicensed firearm was confiscated.
“The third suspect was released as he could not be linked to the crime,” said Traut.
The men, who face charges of murder and attempted murder, were due to appear in court on Monday.