Witnesses reported at least 13 people were killed and dozens wounded in the worst fighting seen in the volatile city in months.
Crowds of people were seen kicking and throwing stones at other unidentified corpses being pulled through the streets.
Ethiopia has denied any of its soldiers were among those captured during Wednesday’s battle, despite an Associated Press photographer’s eyewitness account to the contrary.
The scene was reminiscent of images of the 1993 U.S. Black Hawk incident in Somalia, when American troops, shot down from their helicopter, were dragged through the streets of the capital.
The fighting erupted in the early morning Wednesday when Somali forces entered a neighborhood in southern Mogadishu known to be an Islamic militant stronghold.
Mohamed Ali Nur, Somalia’s ambassador in Kenya, said the soldiers were sent to stop militants from attacking government buildings, which have become common targets for mortar attacks since the interim government took control of the city with help from Ethiopian troops in December.
The Somali-Ethiopian forces drove a popular Islamist movement from the city, but Islamic insurgents responded with guerilla-style attacks that have killed dozens this year.
African Union peacekeepers, meant to replace Ethiopian forces and help maintain security, have been in the country for two weeks but were not involved in Wednesday’s fighting.
The commander of AU forces in Somalia pleaded Tuesday for reinforcements for his 1,500 soldiers.
The AU plans for an 8,000-soldier force, but Uganda is the only country to deploy forces to Somalia so far.
Insurgents warned against any outside involvement and vowed to attack the AU peacekeepers. Two Ugandans have been injured in attacks since arriving March 6.