MOGADISHU (Reuters) - About three blasts, possibly from mortar bombs, echoed on Tuesday across the Somali capital where the authorities had imposed a security lock down on the eve of a presidential vote.
There were no immediate reports of casualties or claims of responsibility, although the Islamist al Shabaab group often launches attacks in Mogadishu and says it wants to disrupt Wednesday's vote to be held behind the airport's blast walls.
After months of delays, 329 newly sworn-in members of parliament will choose whether to back President Hassan Sheikh Mohamud for a second term or one of 21 rivals.
In preparation, the authorities blocked main roads in the capital and prevented vehicles from driving near the airport, which is patrolled by African Union peacekeepers AMISOM and surrounded by high concrete barriers.
"All those involved in the election, directly or indirectly, are apostates," Al Shabaab spokesman Sheikh Ali Mohamud Rage had told Reuters earlier in the day.
He said the group would take "tough measures" against those involved and accused foreigners of guiding the vote in a nation heavily dependent on international support as it rebuilds after years of conflict and battles the Islamist insurgency.
Presidential candidates have promised to improve security and the economy. Until now, a construction boom in the bombed out capital has yet to spread far across the rest of the nation. A severe drought is threatening a new national food crisis.
Rival candidates have also accused each other of vote-buying, a practice Western donors have sought to stamp out. Diplomats say corruption continues to hamper development.
Al Shabaab, which once ruled most of Somalia and wants to impose its strict interpretation of Islam on the nation, often launches gun and bomb raids in Mogadishu. But it now controls increasingly smaller pockets of territory.
Faced with the impossible task of securing polling stations across the nation, the government and its Western backers dropped an initial plan to give each adult a vote.
Instead, about 14,000 clan elders and regional figures chose the 275 members of the lower house of parliament and 54 members of senate. Those lawmakers will pick the president on Wednesday.
The system is a modest improvement on 2012, when just 135 elders picked parliament, which chose the president.
Experts said President Mohamud, who has had to fend off accusations by Western donors of corruption in his government, can rely on the loyalty of about a third of the new lawmakers, giving him an edge but not a guarantee of victory.
Writing by Edmund Blair; Editing by Alison Williams