At least 80 people, including many civilians, have been killed in intensified fighting in Somalia over the past two days, according to hospital sources.
Around 300 people have been wounded in the fighting - some of the fiercest Mogadishu has seen since the transitional government took over the capital in December.
An Ethiopian helicopter scouring the Somali capital for insurgents was shot down and crash-landed near Mogadishu's International Airport on Friday.
Smoke billowed from the landing site, after the helicopter was shot down by an anti-aircraft missile. It was unclear how many people were on the helicopter and if there were any survivors.
A barrage of shelling and gunfire continued in the coastal capital Friday, a day after Ethiopian-backed government troops began an operation to clear the city of insurgents using helicopters and tanks.
The Ethiopian operation was meant to purge the city of militants - believed to be a combination of clan members and remnants of an Islamist group that ruled most of the country for six months.
Sounds of gunfire filled the air less than one week after the government and elders of the city's dominant Hawiye clan agreed to a ceasefire.
The government, attempting to assert its authority over the anarchic Horn of Africa country, said it would try to pacify the capital before an April 16 EU-backed national reconciliation conference that is set to draw some 3,000 participants.
But attacks have been increasingly common since the government took control of Somalia, which has been without effective rule since 1991.
Thousands of civilians have fled the capital as a result of renewed fighting, with the UN's refugee agency saying some 57,000 have left since the beginning of February.
"We are escaping with our children to wherever we can get security," said Mohamed Awale, a Mogadishu resident.
Ethiopian president Meles Zenawi said two thirds of his troops had already been withdrawn from Somalia, as an African Union (AU) force of 1,500 moved in to help secure the capital.