Militants fired mortars at the presidential palace Tuesday, hours after the Somali president moved in, but he was unhurt in the attack that killed aboy and wounded three of the youth's siblings, witnesses and officials told the Associated Press.

Insurgents launched their most violent attacks since the interim government took control of Mogadishu at the beginning of the year, firing six mortars at the hilltop palace only hours after President Abdullahi Yusuf moved to the capital from the government's southern stronghold of Baidoa.

Yusuf was unharmed during the 10-minute attack, presidential spokesman Hussein Mohamoud Hussein told the AP.

Ethiopian tanks quickly sealed off the area and several hundred Ethiopian and government troops created a48-metre protective cordon around the palace, according to an AP reporter.

Elsewhere in the increasingly violent capital, a remote-controlled roadside bomb killed two government aides and seriously wounded a bodyguard, another witness said. Gun battles also erupted in the city.

Somalia's government and troops from neighbouring Ethiopia drove out a radical Islamic movement late last year, but the government is now struggling with a growing insurgency and the Ethiopians have started pulling out.

African Union peacekeepers who began arriving last week also have come under attack. The peacekeepers are the first in the country in more than a decade.