MOGADISHU, Somalia -

Mortar rounds and rockets slammed into Somalia's capital early Monday in a series of attacks that killed a 6-year-old boy and his father as they slept and wounded at least seven people, witnesses said.

The violence, which hit residential areas as well as the presidential palace, a radio station and a police station, was among the worst since Somalia's government moved into the capital late last year. Somali troops, with the help of soldiers from neighboring Ethiopia, drove out a radical Islamic militia known as the Council of Islamic Courts.

"We were sleeping when a heavy explosion rocked our house. It landed on the roof of our balcony," said Shamsa Ahmed, whose father and brother were killed in the mortar attack. Four others were wounded.

A separate rocket attack on a police station also wounded three others. It was not immediately clear whether there were casualties from other attacks outside the presidential palace and a radio station.

Meanwhile, a group that has claimed responsibility for recent attacks in Mogadishu warned that it would shoot down planes using Mogadishu International Airport.

"They have to know that the resistance will shoot down planes that use Mogadishu airport. All the necessary equipment for carrying out this operation is in our hands," according to the statement by the Popular Resistance Movement in the Land of the Two Migrations. The statement was dated Sunday and posted on the Islamic courts' Web site.

Somalia's deputy defense minister blamed the recent violence on remnants of the radical Islamic movement that was pushed out of Mogadishu and parts of the country's south earlier this year. The Islamic group has been accused of harboring al-Qaida suspects, which it denies.

The Islamic movement, which still has support in Mogadishu, has vowed to wage an Iraq-style insurgency, and attacks in the capital have happened almost daily in the past month.

"A day hardly passes here without admitting civilian casualties resulting from overnight mortar and rocket attacks," said Dr. Sheik Doon Salad Ilmi, director of Mogadishu's Medina Hospital.

Deputy Defense Minister Salad Ali Jelle said the attackers are linked to al-Qaida and that authorities were searching for them. "This is a cowardly attack," Jelle said. "Government troops will crack down on these terrorist elements."

A demonstration in the southern port city of Kismayo ended in violence Sunday. An explosion went off as the army chief prepared to address the rally of supporters of a proposed peacekeeping force, and government troops fired into the crowd in response. At least five people were killed.

It was not immediately clear what caused the blast.

Kismayo, Somalia's third-largest city, was the last major one held by the radical Islamic movement.

Somali Information Minister Madow Nunow Mohamed said the Cabinet has approved an anti-terrorism law, which now must be signed by the president. The law calls for life imprisonment, execution or confiscation of property of those convicted of organizing, carrying out or funding terrorist acts.

The African Union has proposed a peacekeeping mission to help Somalia's struggling transitional government stabilize Somalia, particularly after Ethiopia withdraws its forces.

Said Djinnit, head of the AU's Peace and Security Council, said the group is meeting this week to discuss a starting date for the deployment and to work out details.

"I think the biggest challenge for us remains the creation of positive conditions, and logistics," he said.

Somalia has not had an effective national government since 1991, when warlords overthrew dictator Mohamed Siad Barre and then turned on one another, throwing the country into anarchy. The transitional government was formed in 2004 with U.N. help.