Lebanese security services locked down central Beirut on Wednesday ahead of a meeting of politicians aimed at discussing ways out of a political crisis that has paralyzed government and fueled a wave of street protests.Activists mobilizing against government failures including a waste disposal crisis that has allowed garbage to pile up in Beirut have called protests to coincide with the "national dialogue" called by parliamentary speaker Nabih Berri.Hundreds of soldiers lined entrances to downtown Beirut early on Wednesday, locking down the area home to the parliament building where the dialogue was due to begin at 11 a.m. (0800 GMT). Armored vehicles lined streets in the sweltering summer heat as a sandstorm engulfed Lebanon for a second day."This government is afraid of its people, closing the roads to a constitutional institution - the parliament. We should be protesting today in front of the parliament, peacefully," said Marwan Maalouf, one of the founders of the "You Stink" campaign."This government is scared of the voice of anger of its people that has been going into the street for two months," Maalouf said in a televised interview with New TV.He said the movement would go ahead with a protest at 6 p.m. in nearby areas.A small group of protesters, some holding Lebanese flags, had already gathered at one of the newly erected barbed wire barricades blocking the way to parliament.The dialogue comes after several weeks of protests that have occasionally turned violent. The protests have been organized independently of the main sectarian parties, posing a challenge to these parties.Parliament, like other institutions of state, has barely functioned in recent years in a political crisis linked to wider regional turmoil, including the war in neighboring Syria.