SYDNEY — Australia has turned around more than 600 asylum seekers trying to reach its shores on 20 separate boats since enacting controversial new border controls in December 2013, Immigration Minister Peter Dutton said on Thursday. Australia has vowed to stop asylum seekers reaching its shores, turning boats back to Indonesia when it can and sending those it cannot to camps in impoverished Papua New Guinea and Nauru in the South Pacific for long-term detention. The United Nations and human rights groups have criticized Australia over its tough asylum-seeker policies, which conservative Prime Minister Tony Abbott has further strengthened and defended as necessary to stop deaths at sea. In June, reports that Australia paid people-smugglers bound for Australia thousands of dollars to turn their boat back to Indonesia caused tensions with Jakarta, plunging relations to their lowest point in more than a year. Australia's Department of Immigration routinely does not comment on “on water” operations, so Dutton's announcement provides the most complete picture to date of the scale of the turn-back operations. — Reuters