“It is not yet known whether it is a serial killer but a team has been appointed to investigate this,” the department’s Jimmy Machaka said.
Brigadier Hangwani Mulaudzi said on Tuesday there had been three murders and an assault and robbery since the beginning of the year.
A university cleaner was stabbed to death on Friday and her personal items stolen.
“Her body was found near the university’s administration block,” Mulaudzi said.
A university student was hospitalised after she was assaulted and robbed in May. Police could not be reached to confirm the extent of her injuries or the location of the attack.
The bodies of two girls, aged eight and nine, were found next to a cemetery in Golgotha, near the university. They were believed to have been kidnapped from their schools.
The nine-year-old’s body was found in April, and the younger girl’s in June.
Mulaudzi said it was premature to say whether a serial killer was behind the attacks.
“All four cases have been centralised and a task team has been appointed to investigate the attacks,” he said.
“We must go back to the dockets and check the modus operandi to see whether there are any similarities.”