Sunni supporters of Lebanon's prime minister-designate and Shiite rivals from the parliament speaker's political faction traded gunfire in a Beirut neighborhood on Sunday.
Security officials said one civilian was killed and two others were wounded in the first outbreak of violence since this month's elections.
Automatic rifle fire and three explosions were heard in the brief gun-battle that underlined the continued sectarian tensions despite recent pledges by political leaders to work together. Those pledges followed a bruising election campaign.
Hours earlier, the Western-backed billionaire who is to become the country's next prime minister, Saad Hariri, was holding talks with his predecessors as part of the delicate process of forming a government that can unify the deeply divided country.
Lebanese troops cordoned off the Aisha Bakkar neighbourhood in the capital's Muslim sector and deployed in force to restore calm today evening, security officials said on condition of anonymity because they were not authorized to speak to the media.
They said the dead victim was a 30-year-old woman shot outside her home.