Somali government forces and Ethiopian allies rained down mortars and rockets on Islamist fighters dug in near a southern port town today to start a battle that could be the last stand for the Islamists.
As night fell, the Islamists who fled Mogadishu three days ago to take refuge around the towns of Kismayu and nearby Jilib, fired back from trenches in scrubby bushland, witnesses said.
"We will continue fighting the Ethiopians from everywhere until they leave Somalia," Islamist spokesman Abdirahim Ali Mudey said from the area.
Ethiopian troops man a mobile artillery battery in Somalia's capital Mogadishu
The besieged Somalia Islamic Courts Council (SICC) has rallied several thousand fighters at Jilib, just north of the port town of Kismayu on the shores of the Indian Ocean, after a retreat south 300 kilometres from the capital Mogadishu.
Fearing a blood-bath, residents ran for their lives, carrying blankets, food and water on their heads. "Two-thirds of the population in Jilib have fled the town... nearly 4,700 have fled," aid worker Osman Mohamed said.
The Islamists have built trenches with bulldozers and have more than 60 "technicals" - pickups mounted with heavy weapons - supporting some 3,000 fighters, witnesses say.
Amid confusing initial reports, residents said they saw mortars and rockets falling on deserted houses in Jilib from Bulobaley on one of two roads the Ethiopian-Somali government force had been marching along towards the Islamist defences. Jilib lies about 45 kilometres north of Kismayu, where senior Islamist leaders Sheikh Hassan Dahir Aweys and Sheikh Sharif Ahmed are based.
The intervention of Ethiopia has reversed the fortunes of the government and the hardline religious SICC, which just two weeks ago controlled the capital and appeared on the verge of routing a weak interim government stranded in a provincial town.
Now the government has control of Mogadishu and the Islamists - without tanks or planes - are fighting with their backs to the sea and Somalia's southern border with Kenya.
Kenya has reinforced its northern border and US forces are also said to be in the region, including the sea, to prevent foreign militants aligned with the Islamists from escaping.
Ethiopia says it has 4,000 troops in Somalia, though many believe that number could be far higher. Somalia's government has not given troop numbers, but is thought by experts to have several thousand.
Islamist leaders called their flight to Kismayu a tactical move to avoid civilian bloodshed in Mogadishu. The SICC - who have been offered an amnesty by the government if they surrender - say they are ready to negotiate with the UN-endorsed interim government, but that the Ethiopian soldiers backing it must first leave.
Born out of sharia courts operating in Mogadishu, the Islamists threw US-backed warlords out of the capital in June before going on to take a swathe of south Somalia. They brought order to Mogadishu for the first time since 1991 when warlords ousted a dictator.
But some of their hardline practices - like closing cinemas and holding public executions - angered some Somalis and fuelled US and Ethiopian accusations they were a dangerous Taliban-style movement.
Both Addis Ababa and Washington say the SICC is linked to al-Qaeda, an accusation the movement says is trumped up to justify foreign intervention.
Ethiopia also accuses arch-foe Eritrea of supporting the Islamists. Eritrea has accused Ethiopia of planting Eritrean identity cards on the battlefield to back up those claims.
Mogadishu residents have greeted the joint Ethiopian and government force with a mix of jubilation, fear and protests.