Factbox: Foreign troop deployments in Somalia

Here are details of incursions into Somalia by foreign troops after residents said Ethiopian military vehicles pushed into neighboring Somalia at the weekend, just weeks after Kenya entered Somalia to fight Islamist militants.

Somalia has been mired in anarchy since warlords toppled military dictator Mohamed Siad Barre in 1991.

* THE 1990s

-- In August 1992 the first contingent of U.N. troops under the United Nations Operation in Somalia, or UNOSOM, arrived to monitor a ceasefire in Mogadishu after the fall of Siad Barre. In December 1992 the United Nations authorized member states to form the Unified Task Force (UNITAF) led by the United States to deploy troops to deliver humanitarian aid. UNITAF deployed some 37,000 troops.

-- In May 1993 a second U.N. force, UNOSOM II, took over from the U.S. troops. On June 5, 1993, 23 Pakistani soldiers were killed in fighting with warlord Mohammed Farah Aideed's forces. The U.N. mission was dealt a fatal blow when 18 U.S. rangers sent to hunt down Aideed were killed in Mogadishu.

-- Remaining U.S. forces withdrew and UNOSOM II was withdrawn in March 1995, leaving the local warlords to fight on. Some 150 U.N. personnel were killed during the mission.

* 2006-2010:

-- In June 2006, Islamist militia loyal to the Somalia Islamic Courts Council seized Mogadishu after defeating U.S.-backed warlords.

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

-- AMISOM, an African Union peacekeeping force, was deployed in early 2007. It is now made up of Ugandan and Burundian troops and has been largely responsible for keeping the interim authority, the Transitional Federal Government, in power.

-- Since Ethiopian troops withdrew in January 2009, the biggest threat has come from al Shabaab which controls much of southern and central Somalia.

* 2011:

-- Kenya deployed troops into Somalia in mid-October in pursuit of the insurgents it has blamed for a series of kidnappings on Kenyan soil and frequent assaults on its security forces in the border province of North Eastern.

-- Kenya's military chief said on October 29 that Kenya would end its campaign in Somalia only when it was satisfied it had stripped al Shabaab of its capacity to attack across the border. Al Shabaab has been fighting to impose a strict version of sharia law. The Islamists pulled most of their fighters out of Mogadishu in August, and have resorted to suicide attacks and guerrilla-style tactics against AMISOM troops.

-- Residents said Ethiopian military vehicles pushed 80 km into Somalia on November 19. Its troops were also seen in Kenya, near its border with Somalia.

-- The leaders of Kenya, Uganda and Somalia agreed last week to intensify efforts to defeat al Shabaab.

(Reporting by David Cutler, London Editorial Reference Unit).

Source: Reuters