BEIRUT, (AP) – Sunni supporters of Lebanon’s prime minister-designate and Shiite rivals from the parliament speaker’s political faction traded gunfire in a Beirut neighborhood 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 gunbattle 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 neighborhood in the capital’s Muslim sector and deployed in force to restore calm Sunday 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.

The fighting was between supporters of Hariri, a Sunni who leads the parliamentary majority, and rival followers of the Hezbollah-allied Shiite parliament speaker Nabih Berri.

In May 2008, heavy clashes erupted between the same rival factions. Hezbollah along with Berri’s Amal movement later swept through Sunni neighborhoods to briefly seize control. A political agreement that called for a national unity government and the June 7 parliamentary elections restored peace for about a year.

Hariri was named Saturday by Lebanon’s president to become the next prime minister after his pro-Western coalition defeated a Hezbollah-backed alliance in the election. All major factions have since pledged to turn a new page.

Sunday’s gunfight is not expected to derail the reconciliation efforts, but it showed once again how tensions could quickly spill over onto the streets. It was not clear what sparked the gunfight Sunday, but tension has built up in that neighborhood since Saturday’s celebrations by Hariri’s supporters, who set off fireworks upon the announcement that he was named as prime minister.

Among the challenges facing Hariri is the opposition’s possible demand for veto power in the government — something the pro-Western majority has vowed not to give to the militant group Hezbollah and its allies.

Hezbollah and its political partners negotiated veto power after Shiite gunmen overran Sunni neighborhoods in Beirut and forced the government’s hand in the May 2008 fighting. The veto power has virtually paralyzed the government but ensured a year of relative calm.