Riot police and anti-government demonstrators have clashed for a second night in the Lebanese capital, Beirut, leaving dozens of people wounded. Protesters threw bottles and fireworks at police officers, who responded with tear gas and water cannon. Meanwhile, Interior Minister Raya el-Hassan ordered an inquiry into Saturday's fierce crackdown by security forces that left dozens more wounded. Protests over economic mismanagement by the ruling elite began in October. The clashes are some of the worst violence since the largely peaceful protests started. They triggered the resignation of the Prime Minister, Saad al-Hariri, but talks to form a new government are deadlocked. On Monday, the Lebanese parliament will consider whom to nominate as prime minister, with Mr Hariri expected to return to the post. Riot police and security forces were again deployed in large numbers on Sunday as thousands of protesters returned to the streets. Lebanon's Internal Security Forces said they fired tear gas after demonstrators pelted them with fireworks and stones. The Lebanese Civil Defence said it had treated 46 people for injuries and taken 14 others to hospital, according to Reuters news agency. A protester, Omar Abyad, a 25-year-old nurse who has been unemployed since he graduated two years ago, told Reuters: "They [security forces] attacked us in a barbaric way, as if we're not protesting for their sake, their children." The interior minister demanded the security forces to open a "rapid and transparent" investigation into Saturday's violence but warned against "infiltrators" seeking to use protests to spark "confrontations". Diala Haidar, from rights group Amnesty International, said "security forces used excessive force to disperse an overwhelmingly peaceful protest", adding: "It only sends a clear message that security forces are above the law and will take whatever measures to end the protests when need be." The protests have been the largest seen in Lebanon in more than a decade. They have cut across sectarian lines - a rare phenomenon since the devastating 1975-1990 civil war ended - and involved people from all sectors of society. Demonstrators are angry at their leaders' failure to deal with a stagnant economy, rising prices, high unemployment, dire public services and corruption. Their demands include an end to government corruption and the overhaul of the political system and the formation of an independent, non-sectarian cabinet.