Somalia's president told residents of the only town his government controls Tuesday that they have a week to give up their weapons or "every single gun" would be seized by force.

President Abdullahi Yusuf said his government would pay people for any arms surrendered and that details of the disarmament plan would be released Wednesday.

He did not say why his government decided on the measure, but two lawmakers have been shot in Baidoa, 155 miles from the capital of Mogadishu, over the past week, one fatally. More than 21 others have resigned in disgust, including five on Tuesday.

CountryWatch: Somalia

Meanwhile, the rival Islamic militia has expanded its influence beyond the country's south and Mogadishu to central Somalia for the first time. The government has watched helplessly as the militia tightened its grip since seizing control in June.

Hundreds of Islamic militiamen with dozens of pickup trucks mounted with machine-guns reached Adado district in the central region of Galgaduud and set up an Islamic court on Monday, said resident Sahal Osman.

Somalia's government has no military and relies on a militia loyal to Yusuf.

The Islamic militants have imposed strict religious courts, raising fears of an emerging Taliban-style regime. The United States accuses the group of harboring Al Qaeda leaders responsible for deadly bombings at the U.S. embassies in Kenya and Tanzania in 1998.

The militants have brought a remarkable amount of control to a country that has seen little but chaos since 1991, when longtime dictator Mohamed Siad Barre was toppled.

The current administration was formed two years ago with the support of the United Nations, but it has established no real authority.

Five ministers resigned Tuesday, bringing the total number of lawmakers who have stepped down to more than 21. Prime Minister Ali Mohamed Gedi presides over more than 70 Cabinet ministers and their deputies.

Gedi barely survived a no-confidence vote in parliament over the weekend, but insisted Tuesday that government would continue to function.

"My government has survived political turmoil, and right now I hope it will stand on its own two legs soon," Gedi told journalists after Tuesday's resignations.

Foreign ministers of the regional Intergovernmental Authority on Development met in neighboring Kenya Tuesday to discuss the situation in Somalia, issuing a statement that "urged countries within and without the region to strictly adhere to the United Nations Security Council arms embargo."

An arms embargo imposed by the United Nations has been in place since 1992, but all sides in the Somali conflict have violated it.

The foreign ministers also said their respective chiefs of defense staff would meet as soon as possible to prepare a mission plan necessary for a peacekeeping operation in Somalia. The Islamic militia in Somalia has rejected any peacekeeping mission, but the transitional government has repeatedly called for one.

The regional group mediated talks beginning four years ago that led to the formation of Somalia's government. Besides Somalia, group members include Djibouti, Eritrea, Ethiopia, Sudan, Uganda and Kenya.

On Tuesday, Kazakhstan said it was investigating reports that a plane bearing the ex-Soviet republic's national flag delivered weapons for Islamic militants in Somalia twice last week. Somalia's government alleges the deliveries were arms from Eritrea.

Officials in Kazakhstan, an oil-rich Central Asian nation, had been involved in a string of illegal arms dealing scandals after the 1991 Soviet collapse that included sales of military equipment to countries including Ethiopia and Congo. Kazakh air operators also often make their planes available for charter.