JOHANNESBURG (REUTERS) - Zimbabwean President Robert Mugabe's wife Grace whipped two South African women in a Johannesburg hotel room with an electric cable, the mother of one victim said, adding that the attack must be punished.

Debbie Engels told Reuters her daughter Gabriella, a 20-year-old model, suffered a gash on her forehead that required eight stitches and another on the back of her head that needed six.

Engels did not witness the attack and Reuters has not been able to verify key aspects of the allegations independently. South African media published pictures of Gabriella with a gash in her forehead.

South African police confirmed on Wednesday (Aug 16) that Mugabe, 52, remained in the country and had applied for diplomatic immunity. They also confirmed that she had failed to appear at a court hearing on Tuesday relating to the accusations.

Mugabe's spokesman, George Charamba, and Zimbabwe's Information Minister, Chris Mushowe, did not respond to multiple requests for comment.

South Africa's main police spokesman said officers were"still investigating" the case, which related to assault with intent to cause grievous bodily harm.

Mugabe is a potential contender to succeed her 93-year-old husband.

'SCREAMING WOMAN'

Engels said her daughter told her the incident happened on Sunday when Gabriella and two friends went to a hotel in Johannesburg's upscale Sandton shopping and financial district to see a young man they had met the previous day.

Reuters tried to contact Gabriella but did not receive a response. Engels said Gabriella's two friends did not want to speak to the media, and Reuters was unable to contact them.

The girls told her they had no idea the man, introduced to them only as Bellarmine, was Chatunga Bellarmine Mugabe, one of the two adult sons of Zimbabwe's leader of the last 37 years, Engels said.

Chatunga and his brother, Robert Junior, have been living in Sandton for most of this year. Reuters was unable to reach them for comment.

Recounting her daughter's story, Engels said Gabriella told her the three girls were waiting in a room with a mutual friend and another man when a second man rushed in, saying the girls must hide in the bedroom and keep quiet.

Before they could do so, an irate woman burst in brandishing an electric extension cable in her hand.

"The next minute this woman comes in screaming, calling them names and whatnot and demanding to know where her sons were," Engels said.

"They kept telling her 'They're not here,'" she said.

Gabriella said that Mugabe's security guards, who had followed her into the room, stood by and watched throughout, Engels said. Mugabe's spokesman did not respond to Reuters requests for comment.

"She had an electric cord wrapped around her hand and she started attacking them. She hit my daughter with a plug socket," Engels said.

Gabriella told her that she eventually escaped and got help from one of the hotel security guards. It was only when she asked who her attacker was, so that she could file a complaint, that she discovered it was Grace Mugabe.

Engels said a hotel security guard told her daughter: "No, that's Mugabe's wife."

The other two girls were not hurt, she said.

After Gabriella had been taken to hospital, Engels said she Googled a picture of Grace Mugabe and showed it to her daughter and asked if she was her attacker. Her daughter said yes.