LIMA, Peru — Peru indefinitely shut the famed ancient ruins of Machu Picchu on Saturday in the latest sign that anti-government protests that began last month are increasingly engulfing the South American country. There were 417 visitors stuck at Machu Picchu and unable to get out, more than 300 of them foreigners, Tourism Minister Luis Fernando Helguero said at a news conference. Until recently, the protests had been concentrated in the country’s south.