"Smoke billowed from the cabin and it turned towards the ocean," one witness, Swiss journalist Eugen Sorg, told Reuters. "It crashed at the south end of the airport runway."
The fighting has killed at least 30 and wounded more than 200 as insurgents respond to a major offensive by Ethiopian and Somali forces targeting militias resistant to the transitional Somali government. Hawiye leaders supported the Islamic Courts Union rule and have been excluded from the transitional government.
The government, formed after Ethiopian troops ousted the Islamic Courts Union from power in December, remains fragile. A cease-fire signed between the government and the city's dominant Hawiye clan appeared meaningless Thursday night as Ethiopian and Somali tanks were met with the mortars and rocket-propelled grenades of the insurgents.
"The cease-fire is broken," local journalist Abdurrahman Warsame told the Washington Post. "The future seems bleak to me. I don't think they have a way to compromise now. It is really not that good."
The helicopter was hit after targeting an insurgent stronghold.
The International Committee of the Red Cross confirmed the ferocity of the new fighting saying dozens had been killed since Thursday and more than 220 wounded, most of them civilians with bullet, grenade and other shrapnel wounds.
"The population of Mogadishu is caught up in the worst fighting in more than 15 years," the agency said in a statement Friday.
On Thursday, insurgents joined by angry civilians dragged the bodies of government soldiers through the streets reminiscent of the Black Hawk Down incident in 1993 when militias shot down a U.S. helicopter and Somalis dragged the soldiers' bodies through the streets.
Ethiopian troops are seen as occupiers by many Somalis and while the African Union pledged an 8,000-strong peacekeeping force to replace the Ethiopians, only 1,200 Ugandans have been sent.
The fighting has put thousands of civilians in danger, and according to the United Nations, 12,000 civilians have fled Mogadishu in the past week. U.N. Secretary-General Ban Ki-moon said he was "deeply disturbed" by the violence, especially the airstrikes, tanks and heavy artillery in Mogadishu's densely populated areas.
Somalia's government led by President Abdullahi Yusuf, who is from the Hawiye's rival Darod clan, and Prime Minister Ali Mohamed Gedi scheduled a reconciliation conference for mid-April and are confident it will move forward despite the violence.