At least 80 people protesting in New York against the US financial system and Wall Street practices were arrested  in the first big crackdown since demonstrators began camping on city streets a week ago. \"About 80 arrests were made,\" a spokesman for the New York Police Department told AFP. Most of the detained protestors were accused of blocking traffic and government facilities, and resisting arrest.One person was charged with assaulting a police officer and one officer suffered a shoulder injury, the department spokesman said. The main protest website, occupywallst.org, said between 80 and 100 people had been arrested, most of them in the Union Square area of Manhattan. Footage on the site showed police corralling a crowd with orange plastic mesh. The Occupy Wall Street protest began on September 17 in the vicinity of the heavily guarded New York Stock Exchange. A week later, a hardcore of demonstrators remained camped around the clock in a small nearby park. Although only loosely organized, protestors have persevered despite a heavy police presence and several days of rain. The demonstrators communicate constantly through YouTube, Twitter and other online platforms.They say they are motivated by anger against the huge disparity between the very rich in the country and the growing number of people struggling in the aftermath of the US financial crisis and recession.