Nairobi  - The United Nations children's agency UNICEF Tuesday condemned the recent stoning to death of a 13-year-old Somali girl for adultery in the port town of Kismayo, which was taken over by Islamist insurgents in August.

The girl, Aisha Duhulow, was last week stoned to death for adultery under Islamic law, or sharia. Initial reports said that the girl was in her twenties.

UNICEF said that reports indicated the girl had not committed adultery, but been raped by three men while walking to visit her grandmother in the capital Mogadishu.

The Islamic authorities said that the girl had confessed to her crime and repeatedly asked for the full penalty under sharia.

However, witnesses told the BBC that she begged for her life before being buried up to her neck in the ground and stoned by around 50 men in front of over 1,000 spectators.

"This is a tragic and deplorable incident" said UNICEF Representative for Somalia, Christian Balslev-Olesen. "A child was victimized twice - first by the perpetrators of the rape and then by those responsible for administering justice."

Insurgents have been fighting Somalia's transitional federal government since Ethiopian troops helped oust the Union of Islamic Courts in early 2007.

However, main insurgent group al-Shabaab has rejected the deal and vowed to keep fighting until Ethiopian forces leave Somalia.

The Horn of Africa nation has been plagued by chaos and civil war since the ouster of dictator Mohamed Siad Barre in 1991. (dpa)