Protests have rocked Santiago for a month in the biggest crisis to hit the South American nation since its return to democracy in 1990.

December to February -- the southern hemisphere summer -- is a key time for tourism in Chile, when many international visitors pass through Santiago on their way to treks in Patagonia, while domestic tourists head to the beaches.

Chile's unrest is the latest in a flare-up of protests in South America and around the world - from Beirut to Barcelona - each with local triggers but sharing in common anger at ruling elites and inequality.