A Somali teenager accused of killing a tuk-tuk driver who she alleged had tried to rape her has been released from custody in Egypt.

The 15-year-old had been held for four days after handing herself in to authorities, local media report.

But police and medical examiners agreed there was evidence to show she had likely acted in self-defence, Egypt's prosecutor's office said.

She was released on Friday pending further investigation.

According to Ahram Online, the girl told police the driver had taken her to a remote spot where he had tried to rape her.

But she fought back, injuring her hands on his knife before managing to wrestle it from the alleged attacker.

She then stabbed him and fled.

The unidentified man's body was found in the city of Giza, near the capital Cairo, on 17 May.

The case had already caught the attention of social media users in Egypt, who called on high-profile lawyers and groups to help the girl.

Research suggests sexual assault and harassment are common in Egypt, with a 2013 UN study finding 99.3% of girls and women in the country reporting to have experienced some form of sexual harassment in their lifetime.

However, despite recent changes to the law to increase penalties for those found guilty, Egyptian authorities have been accused of frequently failing to investigate and prosecute men accused of sexual harassment or assault against women and girls.