Two powerful blasts rocked the Somali town of Baidoa within minutes of the interim president leaving the parliament there, but he escaped unhurt.
Five members of President Abdullahi Yusuf's entourage and six alleged assailants died in the blasts, says the country's foreign minister.
The largely powerless government in Baidoa is in a tense stand-off with the Union of Islamic Courts who run much of southern Somalia.
Last week, a powerful warlord threatened to kick the government out of Baidoa by force if they did not leave.
Two alleged attackers were arrested, but ministers say it is too soon to say if al-Qaeda or anyone else is behind the attack.