Somali insurgents waging war in the country's capital Mogadishu used mortars to target Aden Adde International Airport on Saturday as an African Union military plane landed, Radio Garowe reported.

Several mortars hit inside airport grounds but caused no damage and the AU military plane landed safely, according to AU Mission in Somalia (AMISOM) spokesman Major Bahoku Barigye.

Somali government forces responded to the mortar attack by shelling the capital's Bakara Market, which the interim government has long suspected is home base for anti-government rebels.

AMISOM peacekeepers driving tanks entered city streets in a show of force.

At least 10 civilians were killed and 17 others wounded in the shelling, witnesses told Radio Garowe.

Al Shabaab militants claimed responsibility for the mortar attack. Last week, al Shabaab issued a threat to shoot down airplanes landing at Mogadishu's airport.

It was the third mortar attack on the airport in a week, sparking street battles and artillery barrages that have killed upwards of 50 civilians.

On Thursday, Somali Prime Minister Nur "Adde" Hassan Hussein's private plane landed safely at Aden Adde International Airport.

Ethiopians killed

At least three Ethiopian soldiers were killed in a roadside explosion as their convoy drove towards Mogadishu, witnesses reported.

"Ethiopian army trucks who came from Afgoye and were heading to Mogadishu were targeted in a heavy explosion and I saw dead bodies fall out of the cars," said witness Khadar Mohamed, who fled Mogadishu violence months ago.

Ethiopian soldiers opened fire in panic but no one was wounded in the subsequent gunfire.

Islamic Courts spokesman Abdirahim Isse Addow claimed responsibility for the roadside bomb, adding that Ethiopian forces "suffered heavy casualties."

An Islamist-led insurgency has raged in much of south-central Somalia since December 2006, when the Ethiopian army dislodged Islamic Courts rulers from Mogadishu.

Upwards of 9,500 civilians have been killed so far and 860,000 forced to flee their homes.

The UN estimates that nearly 3 million people in Somalia are in need of food assistance, but the humanitarian situation has been worsened dramatically by insurgent violence and piracy along the coast.