FACTBOX: Somalia, a country torn apart

(Reuters) - Ethiopian troops supporting Somalia's Western-backed government quit their main bases in Mogadishu on Tuesday, witnesses said.

The Horn of Africa nation has had no effective government since warlords ousted dictator Mohamed Siad Barre in 1991 then turned on each other. Here are some details of the conflict:

* ISLAMIST RULE:

-- In June 2006, an Islamist militia called the Somalia Islamic Courts Council seized Mogadishu after defeating U.S.-backed warlords. Washington accused the Islamists of having links to Osama bin Laden's al Qaeda.

-- With tacit U.S. approval, Somalia's neighbor Ethiopia sent troops to defend the government against an Islamist attack on Baidoa in December 2006. The force advanced rapidly, taking Mogadishu and driving the Islamists to Somalia's southern tip.

* INTERIM GOVERNMENT:

-- Lawmakers had elected warlord Abdullahi Yusuf president and Ali Mohamed Gedi prime minister to run the 14th attempt at government since the fall of Barre.

-- Gedi resigned in October 2007 and was succeeded by Nur Hassan Hussein as prime minister. Yusuf sacked Hussein in December 2008 and named former interior minister Mohamed Mohamud Guled as premier, snubbing a vote by parliament to reinstate Hussein.

-- Yusuf resigned on December 29.

* BLOODSHED AND HUNGER:

-- Violence in Somalia has killed more than 16,000 people since the start of 2007 and uprooted 1 million. A third of the population rely on emergency food aid and the chaos has helped fuel kidnappings and piracy off the coast.

-- For months, the transitional government and African Union have pleaded with the United Nations to send a robust peacekeeping force that could take over from 3,500 AU troops, who say they are incapable of stabilizing Somalia.

* PEACE DEAL IN DOUBT:

-- The government had initialed a peace deal in June 2008 with some opposition figures. The deal called for the rapid deployment of U.N. peacekeepers.

-- August 2008 talks in Djibouti were rejected by a hardline opposition faction and al Shabaab militants suspected of being behind a wave of car bombings.

* PIRACY: