In a surprise ruling, judges at the International Criminal Court said Thursday that they could exercise jurisdiction to investigate the deportation of hundreds of thousands of Rohingya Muslims from their homes in Myanmar as a crime against humanity.

The judges’ 2-to-1 decision opened a path toward possible accountability for ferocious attacks by security forces on civilians that began a year ago and caused immense suffering as some 700,000 men, woman and children struggled to cross the waterlogged border into Bangladesh.

A recent United Nations report described the campaign as genocide, with an estimated 10,000 deaths; it offered harrowing accounts of gang rapes and the widespread destruction of villages.

Despite an international outcry, the campaign by Myanmar’s army was carried out with impunity as the country’s civilian leaders declined to criticize the violence. To this day, Myanmar’s de facto leader, Daw Aung San Suu Kyi, has refused to hold the nation’s military leaders accountable.