One woman was reportedly killed and several others injured in a shootout in the West Beirut district of Aisha Bakkar on Sunday evening. The clashes erupted between militants of the Shiite Muslim Amal Movement, loyal to House Speaker Nabih Berri, and supporters of the predominantly Sunni Muslim Future Movement headed by Prime Minister-designate Saad al-Hariri. Heavy gunfire and rocket-propelled grenades (RPGs) were heard in the mixed Sunni and Shiite neighborhood as masked gunmen took the streets. Security forces and the Lebanese army quickly deployed in the area and its environs to disperse the crowds and contain the clash, which reportedly spread to the neighboring Mar Elias district. Reports said the woman was killed by sniper fire while looking out her balcony. A Lebanese army soldier was also wounded by sniper fire, according to TV reports. It remains unknown what triggered the shooting, only one day after Hariri was officially declared prime minister-designate and three days after Berri was reelected speaker. But "provocative" celebratory gunfire and fireworks following the election of Berri Thursday and the designation of Hariri Saturday sparked tension between Amal and Future loyalists. The first reported bloody skirmish between supporters of the Hizbullah-led opposition and the West-backed March 14 coalition after the June 7 general elections sparked fears of renewed infighting in the highly polarized country, despite repeated calls for calm by both camps. The Lebanese are also wary of hitting another political stalemate over the government formation, as the Syria-backed opposition insists on veto power in the next cabinet -- a demand the anti-Syrian majority has so far rejected.