Heavily armed Islamic militants captured a key southern port city in Somalia Sunday, according to witnesses.
Since April, A group known as the Council of Islamic Courts has defeated warlords who had divided the country into clan-based fiefdoms since 1992.
The courts have united most of the southern half of the country, promising to deliver peace under Islamic law.
Their capture of Kismayo, a key city on Somalia's coast on the Horn of Africa, filled in a major gap in their southern takeover.
The peaceful takeover prompted the previous leadership, known as the Juba Valley Alliance, to leave the area. It was yet another blow to the country's virtually powerless official government. Somalia's defense minister, Col. Barre "Hirale" Aden Shire, is a leading member of the alliance.
Hirale's deputy, Yusuf Mire Mohamud, said Sunday, "the Juba Valley Alliance has collapsed."
Somalia's interim prime minister called on the United Nations to partially lift an arms embargo on his country to allow for the deployment of African peacekeepers, which he said are necessary to stop the advance of the Islamic courts' takeover.
Somalian Prime Minister Ali Mohamed Gedi told the Associated Press in an interview in neighboring Kenya that al Qaeda members dominate the Council of Islamic Courts.
Gedi and the United States have accused leaders of the Islamic courts of having ties to al Qaeda, Osama bin Laden's terrorist group.
He urged the international community to "act very soon."
The United Nations Security Council was expected to meet in New York on Monday to discuss a partial lifting of the arms embargo that has been in place on Somalia since 1992.
The African Union has endorsed a plan by eastern African states to deploy peacekeepers in Somalia to protect Gedi's weak, but internationally recognized government.
The courts and Gedi's government have agreed to a cease-fire and the courts have recognized the government. But as the capture of Kismayo demonstrated Sunday, the courts have also continued to advance across the country, and have threatened to attack any foreign peacekeepers that enter Somalia.
Gedi said both actions violate the nonaggression agreement his government reached with the group.