April 22 (Reuters) - Explosions shook the Somali capital, Mogadishu, on Sunday for a fifth day of battles between insurgents and allied Somali-Ethiopian troops.

Here is a chronology of events in Somalia:

Nov. 1991 - Power struggle after the overthrow of dictator Mohamed Siad Barre between clan warlords Mohamed Farah Aideed and Ali Mahdi Mohamed kills and wounds thousands of civilians.

Dec. 1992 - U.N. Security Council endorses full-scale U.S.-led military operation. A week later U.S. Marines arrive on Mogadishu's beaches in "Operation Restore Hope".

Oct. 1993 - Eighteen U.S. Army Rangers and one Malaysian are killed when Somali militias shoot down two U.S. helicopters in Mogadishu and a battle ensues. Hundreds of Somalis die in the fighting. Battle depicted in book and film "Black Hawk Down". U.S. mission formally ends in March 1994.

Oct. 2004 - In 14th attempt since 1991 to restore central government, lawmakers elect Ethiopian-backed warlord Abdullahi Yusuf as president. In December, Prime Minister Mohamed Ali Gedi swears in 27 ministers in Kenya.

Feb. 2006 - Lawmakers arrive in the southern city of Baidoa for the first meeting of the country's parliament on home soil.

June 2006 - The Somalia Islamic Courts Council (SICC) seizes the capital Mogadishu from U.S.-backed warlords and take control of parts of southern Somalia.

Sept. 25 - Yusuf escapes a bomb attack that kills five outside parliament in Baidoa.

-- Islamist fighters take over the southern port of Kismayu, Somalia's third largest city.

Oct. 9 - Islamists declare holy war against Ethiopia, which they accuse of invading Somalia to help the government.

Dec. 12 - Islamists tell Ethiopia to leave Somalia within seven days or face war. Fighting starts on Dec. 19.

Dec. 24 - Ethiopian Prime Minister Meles Zenawi says he is waging war against the Islamists to protect his country's sovereignty, Ethiopia's first public admission of military involvement in Somalia.

Dec. 28 - Islamists flee Mogadishu ahead of a joint Ethiopian and Somali government force which captures the city.

Jan. 8, 2007 - Yusuf arrives in Mogadishu for the first time since he became president in 2004.

-- U.S. aircraft strike the southern village of Hayo, after it was believed at least one al Qaeda suspect was sheltering there. Ethiopian and Somali troops had chased the Islamists' last remnants to the area.

Feb. 20 - U.N. Security Council authorises an African Union (AU) peacekeeping mission for Somalia for six months.

March 1 - A Ugandan vanguard of an AU peace force to help the interim government flies into Baidoa.

March 22 - Somalia says al Qaeda has made Aden Hashi Ayro, a militant Islamist commander, its leader in Mogadishu.

March 29/April 1 - Ethiopian helicopter gunships fire rockets on insurgents' strongholds in Mogadishu, the first use of aerial power in the capital. Up to 1,100 people are killed.

April 22 - Fighting strikes Mogadishu for a fifth day killing at least 200. Hundreds of thousands of people have fled their homes, creating a potential humanitarian crisis.

AlertNet news is provided by