Somali Islamist militiamen early Monday fled their last major stronghold Kisimayo towards the Kenyan border after the Ethiopian-backed government troops captured the city, a Somali lawmaker said on Monday.

"Kismayo city is now under interim government's control. The government backed by the Ethiopian troops chased the Islamists this morning," Somali lawmaker Awad Ashara told Xinhua by telephone from Baidoa, the current seat of the UN-backed government.

According to the lawmaker, Prime Minister Ali Mohammed Gedi has offered an amnesty for Islamist fighters handing over their weapons.

"The government is providing amnesty for them provided they hand over their weapons," Gedi told a news conference in Mogadishu on Monday.

Gedi said Islamist fighters had been "misled by international terrorists," stressing that there would be no amnesty for leaders of the Supreme Council of Islamic Courts (SCIC).

Gedi gave a three-day ultimatum to Mogadishu residents from Tuesday to hand over weapons in one of the world's most dangerous and gun-infested cities -- or be disarmed by force.

"They (Islamists) have run away," Ashara added. The retreat from Kismayo is seen as a major reversal for the SCIC, a militia that swept through much of Somalia mid-2006.

The Islamists withdrew to the southern city of Kisimayo on Thursday, after abandoning the capital Mogadishu as a result of heavy fighting involving Ethiopian artillery, tanks and aircraft.

Kenya, which announced Monday it would convene a crisis regional summit on Somalia, has beefed up security at its long and porous frontier with the Horn of African nation in an effort to prevent the Islamists from crossing over.

Reports said U.S. boats were believed to be patrolling the sea off Somalia to prevent SCIC leaders, or foreign militant supporters, from escaping as Ethiopian forces advance cautiously, fearing mines and booby traps.

An Islamic commander, Sheikh Yaqub Ishak, reportedly confirmed his forces had left Kismayo, but said they would not "stop fighting the Ethiopian invader."

The SCIC assumed control of Mogadishu in June, driving warlords out and rapidly extending its influence to much of central and southern Somalia.

Some analysts say the SCIC's popularity stemmed from its ability to transcend the clan enmities that have bedevilled Somalia since the overthrow of former President Mohamed Siad Barre in 1991.

Source: Xinhua