Ethiopian troops supporting Somalia's interim government are killing civilians by slitting people's throats, gouging out eyes and gang-raping women, Amnesty International said Tuesday.
The British-based human rights group says the international community must step in to halt atrocities by all factions in the country.
Somali government troops and their Ethiopian allies have been battling Islamist-led insurgents since early 2007.
In a report published in Nairobi, Kenya, Amnesty quotes eyewitnesses and survivors of what it calls "war crimes and possibly crimes against humanity."
The group says no one is holding perpetrators accountable. The entire population of the capital city, Mogadishu, is scarred from witnessing or suffering such abuses, as well as enforced disappearances and beatings, Amnesty said in its 32-page report.
Ethiopian government officials did not immediately respond to journalists' requests for comment.
Somalia's United Nations-approved interim government has largely failed to impose its authority on the country of some 8 million people, torn apart by inter-clan violence and vulnerable to cycles of drought, flooding and now skyrocketing food prices.
The Ethiopian and Somali governments have frequently denied committing abuses in their fight against what they call al Qaeda-backed terrorists.