BAGHDAD - Protesters blocked roads with burning tyres in southern Iraq and clashed with police in Baghdad on Wednesday, aiming to use economic disruption as leverage to push the government from power and root out state corruption. In Iraq’s southern oil capital of Basra, demonstrators prevented government employees getting to work by installing concrete barriers painted as mock-up coffins of relatives killed in weeks of unrest, a Reuters witness said. Iraq’s large and mainly peaceful protests are the most complex challenge to a Shi’ite Muslim-dominated ruling class that has controlled state institutions and patronage networks since a 2003 U.S.-led invasion toppled Sunni dictator Saddam Hussein. Young, mostly Shi’ite protesters say politicians are corrupt and blame them for Iraq’s failure to recover from decades of conflict and sanctions despite two years of relative calm following the defeat of Islamic State. Security forces shot dead more demonstrators. In the holy city of Kerbala, south of Baghdad, they used live ammunition against protesters, killing two overnight. Two more were killed in clashes near Ahrar Bridge in Baghdad on Wednesday. Near Basra one protester died of wounds from gunfire, police and medics said, bringing the toll since unrest broke out on Oct. 1 to 344 people dead nationwide.