Clashes erupted Thursday in Bolivia’s capital as police used tear gas to disperse a crowd of miners trying to breach the government palace and setting off small dynamite charges, a tactic that has become increasingly common during this second week of nationwide unrest. It was the latest incident in growing social unrest challenging the administration of President Rodrigo Paz, who was sworn in as president late last year, ushering a new era for the Andean nation after nearly 20 years of one-party rule.