A woman was shot and killed in her home in Bhukwini village in Nqgeleni near Mthatha, Lt-Col Mzukisi Fatyela said.
The woman, who lived alone, was killed on Sunday around 10pm.
Neighbours heard gunshots and, after a few minutes, they went to check on her. They found her dead on the couch in her living room and alerted police.
In a separate case, a 17-year-old boy was found dead in Xonya in Engcobo on Saturday around 8pm, Fatyela said.
His body was spotted in an open field by a passerby. The boy had stab wounds to his head.
The motive for the killings was unknown. Murder dockets were opened for both cases.
No arrests had yet been made, Fatyela said.