The offensive, which started Thursday, has sparked the heaviest fighting in Mogadishu since the early 1990s. On Friday, insurgents shot down an Ethiopian helicopter gunship and mortar shells slammed into a hospital, leaving corpses piled in the streets and wounding hundreds of people.
"The victims are the civilians, only civilians are dying and getting wounded in this fighting," said Khadijo Farah Warsame, 45, a mother of seven.
The International Committee of the Red Cross said dozens of people have been killed since Thursday and more than 220 wounded, most of them civilians with bullet, grenade and other war wounds. But the fighting is so severe and widespread that bodies were not being picked up or even tallied. Hospitals were overwhelmed, with patients sleeping on floors.
"All the commercial areas have closed, all the markets, all the stores, and now the people are looking for food. Where can we buy food?" said Farah Hassan, a 50-year-old resident.
Ethiopia says its forces have killed more than 200 insurgents since the assault started.
Somali presidential spokesman Hussein Mohamoud Hussein on Saturday blamed the violence on foreign terrorists, saying al-Qaida had sent fighters to battle government and allied troops.
"These elements were behind the downing of the helicopter yesterday," he said.
The insurgents are linked to the Council of Islamic Courts, which was driven from power in December by Somali and Ethiopian soldiers, accompanied by U.S. special forces. The U.S. has accused the courts of having ties to al-Qaida.
The Islamic courts stockpiled thousands of tons of weapons and ammunition during the six months they controlled Mogadishu. The insurgency will likely last until that stockpile is depleted or key leaders are killed.
The militants have long rejected any secular government and have sworn to fight until Somalia becomes an Islamic emirate. Clan elders have tried to negotiate several cease-fires, but cannot control the young insurgents.
The U.N.'s refugee agency said 58,000 people have fled violence in the Somali capital since the beginning of February.
Somalia has been mired in chaos since 1991, when warlords overthrew dictator Mohamed Siad Barre and then turned on one another.
A U.N. peacekeeping operation in the 1990s saw clashes between foreign troops and Somali fighters, including the notorious downings of two U.S. Black Hawk helicopters in 1993 - which was followed by a firefight that killed some 300 Somalis in 12 hours. The U.S. withdrew from Somalia in 1994.
A national government was established in 2004 but has failed to assert any real control. The administration, with crucial support from Ethiopian troops, toppled the Council of Islamic Courts in December, but insurgents with links to the group have staged attacks nearly every day.
Waves of people have crossed the border into Kenya, raising concerns that Islamic radicals could be trying to hide there.