MINNEAPOLIS — Tense protests over the death of George Floyd and other police killings of black men grew Saturday from New York to Tulsa to Los Angeles. Police cars were set ablaze in several cities, and officers used tear gas and rubber bullets to contain demonstrators as the country lurched toward another long night of unrest after months of coronavirus lockdowns. The protests began in Minneapolis following Monday’s death of George Floyd after a police officer pressed his knee on Floyd’s neck for more than eight minutes. They have since become a national phenomenon as protesters decry years of deaths at police hands.