A helicopter bombing insurgent positions in Somalia's capital was shot down Friday as government and allied troops battled hundreds of gunmen in the streets.

More than 30 people have been killed since the government launched a major offensive Thursday to quash a growing insurgency by Islamic militants, according to hospitals and witnesses.

Somali soldiers and troops from neighboring Ethiopia, who are here to protect the fragile government, were under a severe attack for a second day as they tried to quash a growing insurgency by Islamic militants.

"The helicopter looked like a ball of smoke and fire before crashing," said Ruqiya Shafi Muhyadin, who watched as the helicopter rolled over in the sky and went down in a residential area near the airport.

Mohamud Osman Ashir, who lives near the site, said the helicopter was still burning after the crash.

An Associated Press reporter said an anti-aircraft missile hit the helicopter.

The number of casualties was not immediately clear. On Thursday, fighting killed at least 10 people — but it was likely that many more had died. Hospitals were overwhelmed with the wounded and corpses were scattered in the streets. Doctors trying to tally the numbers said up to 30 people may have died.

Mogadishu resident Abdi Hussein Aboke said he saw 10 bodies in the street Friday, all apparently civilians.

"Some were lying in alleys between houses while others were lying on the streets," he said.

Dahir Mohamed, a nurse with Medina hospital, said 92 wounded patients, including three children, were brought to our hospital since Thursday.

"Ethiopian troops using tanks are in fierce face-to-face fighting with hundreds of Somali gunmen since dawn," said Khalif Mohamed Mumin, who was abandoning his home in search of safety early Friday. "Residents are fleeing in all directions to escape the shelling."

Somalia has seen little more than anarchy for more than a decade. The government, with crucial support from Ethiopian troops, only months ago toppled the Council of Islamic Courts, the militia that had controlled Mogadishu for six months.

But insurgents with links to the Islamic group have staged attacks nearly every day on government and Ethiopian troops. Last week, a cargo plane carrying equipment for African Union peacekeepers here was shot down by a missile during takeoff, killing the 11-person crew.

The United States has accused the Islamic group of having ties to Al Qaeda. On Thursday, a White House report said that despite recent setbacks to Islamic radicals in Somalia, foreign terrorists still are able to find a haven there because of the country's lack of governance, which contributes to a growing security threat throughout East Africa.

The report, submitted to relevant congressional committees, said several Al Qaeda operatives have used Somalia as a base of operations, including the perpetrators of the 1998 bombings of two U.S. embassies in East Africa and the 2002 attacks against an Israeli airliner and a hotel in Kenya.

"The individuals pose an immediate threat to both Somali and international interests in the Horn of Africa," the report said.

The U.N.'s refugee agency said 57,000 people have fled violence in the Somali capital since the beginning of February, including more than 10,000 people who fled the city in the last week.

The figures were based on information provided by non-governmental organizations in Somalia, the U.N. High Commissioner for Refugees said.