By David Ljunggren and Julie Gordon OTTAWA (Reuters) – Police in the Canadian capital Ottawa on Wednesday started warning truck drivers blockading the downtown core that they should depart or face arrest, part of a promised crackdown to end a three-week-old protest over COVID restrictions. “You must leave the area now. Anyone blocking streets … (is) committing a criminal offense and you may be arrested,” read leaflets handed out by police to truckers. “You must immediately cease further unlawful activity.” Police also started ticketing some of the hundreds of vehicles blocking the downtown c…