(Updates death toll, adds Ban Ki-moon, background, quotes)

By Aweys Yusuf

MOGADISHU, Nov 9 (Reuters) - Corpses were scattered on Mogadishu streets on Friday after fighting between Islamist-led insurgents and Ethiopian troops killed at least 20 people, witnesses said.

Locals said one Ethiopian mortar bomb crashed into the Somali capital's sprawling Bakara Market before detonating, claiming eight lives and littering the area with body parts.

Twelve more bodies, including two women, lay in an insurgent stronghold in the north of the city -- a district where rebels dragged dead Ethiopian soldiers along the roads on Thursday.

"Some of the dead civilians were identified by relatives," Mohammed Abdullahi, a resident of the Sqa Holaha neighbourhood, told Reuters by telephone. "Some are still lying here."

In a move likely to dismay the interim government as it and its Ethiopian allies battle the Islamist-led insurgents, U.N. Secretary-General Ban Ki-moon said on Thursday that sending U.N. peacekeepers to Somalia was neither realistic nor viable.

Insecurity had prevented the world body from even sending a technical assessment team, he said.

The Somali administration has long called for U.N. troops to help it stamp its authority on the Horn of Africa country. It is the 14th attempt at government in Somalia, which has been in chaos since 1991 when warlords ousted a dictator.

NO U.N. FORCE

With Ethiopian support, interim government troops chased hardline Islamists out of the capital at the start of this year, but has since faced an Iraq-style rebellion of roadside bombings and assassinations.

In the latest fighting, Ethiopian infantry and tanks pounded insurgent positions in the city, while the rebels responded with automatic gunfire and rocket-propelled grenades.

Aid workers say hundreds of thousands of residents have left Mogadishu this year, fleeing violence that has made delivering humanitarian relief there all but impossible. About 1.5 million Somalis need emergency aid, the United Nations says.

Earlier this year, the African Union (AU) agreed to deploy 8,000 troops to replace the Ethiopians, but so far only 1,600 Ugandan soldiers have arrived. Burundians are set to deploy later this month.

On Thursday, Ban urged AU nations who had pledged troops to the current force to deploy them as soon as possible.

But his conclusion that it was unrealistic to send U.N. peacekeepers angered Mogadishu's dominant Hawiye clan, many of whose members resent the presence of their old enemy Ethiopia.

"We accuse human rights organisations and the United Nations of keeping silent about the massacres the Ethiopians are committing," Hawiye elder Mohammed Hassan Haad told Reuters.

"We are unhappy with their decision not to send troops to Somalia, just when our country needs them most." (Additional reporting by Claudia Parsons in New York) (Writing by Daniel Wallis; Editing by Mary Gabriel)

AlertNet news is provided by