Somalia's capital sees near-daily bloodshed as a powerful insurgent group with links to al Qaeda tries to overthrow the fragile U.N.-backed government and push out some 5,000 African Union peacekeepers. Both sides of the conflict have been accused of indiscriminate shelling.
"We have seen at least 20 dead bodies lying in the streets, most of them civilians," said Ali Muse, the head of Mogadishu's ambulance service. He said about 60 people were wounded as mortars slammed into residential areas.
Thursday's shelling started soon after insurgents fired toward President Sheik Sharif Sheik Ahmed's plane, said police spokesman Abdullahi Hassan Barise.
"The mortars hit the perimeter of the airport," he said. "The plane carrying the president took off safely."
Somalia has not had an effective government for 18 years, since warlords overthrew longtime dictator Mohamed Siad Barre. The warlords then turned on each other, plunging the Horn of Africa nation into chaos and anarchy.
Somalia's lawlessness also has allowed piracy to flourish off its coast, making the waterway one of the most dangerous in the world.