The Islamists in Somalia have expanded their control of the southern portion of the east African country, taking over an agriculturally rich area of Lower Shabelle.

Senior Islamist leader Sheikh Sharif Sheikh Ahmed said Saturday that the Islamists would introduce a strict form of Islamic (sharia) law to the region and he vowed to seize more territory.

The takeover is the Islamists' second major territorial gain in nearly a week, following last Sunday's takeover of the southern port city of Kismayo. The Islamists have gradually expanded their influence over Somalia since defeating warlords in a battle for the capital, Mogadishu, in June.

The country's weak government of President Abdullah Yusef controls only the town of Baidoa. The government has been unable to stop the Islamists' territorial gains.

The United States accuses the Islamists of supporting al-Qaida terrorists. The U.S. says the Islamists are planning to turn Somalia into a Taleban-style Islamic state.

The Somali government has international backing, but virtually no power outside its base of Baidoa. Witnesses say hundreds of Ethiopian troops arrived in Baidoa last Monday to protect the government. Ethiopia's foreign ministry has denied those accounts.

The African Union recently approved a plan to send thousands of peacekeepers to the war-torn country. Islamist leaders have vowed to fight the peacekeeping force if it arrives.