Police responded with tear gas and truncheons. The violent protesters appeared to be from the same fringe groups that targeted anti-government protests in the past. The union activists were still marching separately, although police are interrupting to check bags for gasoline bombs.
Police in Istanbul detained 165 people during May Day events around the city, most of them demonstrators trying to approach a symbolic square in defiance of a ban. Turkey had declared Taksim Square off-limits to May Day demonstrations, and major trade unions marked the day with rallies at government-designated areas.
Labor unions and civil rights groups staged May Day rallies in several US cities on Monday to denounce President Donald Trump's tough policy on immigration.