Somalia's parliament is choosing a new president, in the latest step to end decades of war. No candidate secured the required two-thirds majority in the first round of voting, conducted by secret ballot.
Two candidates then dropped out, leaving a run-off between outgoing President Sheikh Sharif Sheikh Ahmed and academic Hassan Sheikh.
It is the first time in many years that a president will be chosen on Somali soil - a sign of improving security.
However, the al-Qaeda linked group, al-Shabab, still controls many southern and central parts of the country, and has staged frequent suicide attacks in the capital since it was driven out of Mogadishu last year by African Union troops and pro-government forces.
Despite qualifying for the second round, outgoing Prime Minister Abdiweli Mohamed Ali and moderate Islamist Abdulkadir Osoble then pulled out after coming third and fourth respectively. Eighteen candidates were eliminated at the first hurdle.
Analysts say the election is likely to be decided by the clan structure which remains a huge factor in Somali life. However there are also reports of votes being sold.
The BBC's Daud Aweis in Mogadishu describes a mood of real excitement in the city. The election is being broadcast live on several local TV stations, and is being streamed live on an official feed.
The process began five hours late at a police academy in Mogadishu, following tight security checks.
The election was also delayed by the swearing-in of the last batch of MPs and then a vote on whether a group of disputed MPs, including former warlords, could take part. The MPs voted in favour.
A two-thirds majority is also needed in the second round.
If no candidate achieves that, the two best-placed candidates would go to a run-off.
The new speaker of parliament, Mohamed Osman Jawari, has urged MPs to vote with their consciences.
"May God help us to elect a good leader in an atmosphere of tranquillity. We must give the youth of Somalia a bright future," he said.
The process is still in many ways owned by outside powers who have for years been involved militarily and politically in Somalia, the BBC's Mary Harper reports.
She says that it is telling that in recent days the UN, the African Union, the US, Britain and others have issued strong statements on Somalia, some warning that resorting to violence is not an option.
They have invested so much money, time and manpower in trying to solve the Somali problem that they cannot afford to see it fail, our correspondent adds.
Since the overthrow of President Siad Barre in 1991, Somalia has seen clan-based warlords, Islamist militants and its neighbours all battling for control.
.. BBC
.. BBC
