A Polish man with far-right views drove into a busy central square in Krakow on Saturday and opened fire, killing six people and injuring 15 others before police shot and wounded him, authorities said. The attack, which Poland's defense minister described as an "act of terror," happened in Main Square, which is in the heart of Krakow's Old Town and is a major tourist hub in the country's second-largest city. The 25-year-old attacker drove to multiple spots in the square and opened fire at each stop with an automatic weapon, authorities said. Although they didn't release his name, Interior Minister Marcin Kierwiski said the man holds "very radical" and "ultranationalistic" views.