The Zapatistas marked 23 years Sunday of their iconic uprising against the Mexican state that has inspired social movements around the globe as a leading example of autonomous organizing and Indigenous resistance.

The Zapatista National Liberation Army, known as the EZLN, commemorated the anniversary with a private ceremony in Oventic, in the southern Mexican state of Chiapas. The event was closed to the press and people outside the Zapatista community.

The celebration also marked the 20th anniversary National Indigenous Congress, an initiative the Zapatistas first launched as a rallying cry in the early years after the movement emerged to bring together Indigenous peoples from Mexico and other countries to advance their struggles through solidarity.

On Sunday, the EZLN also indicated that the movement will announce its presidential candidate for the 2018 elections — which it has already indicated will be an Indigenous woman — in May after a process of community consultation. According to representatives, the consultation process was extended beyond the original timeline due to security concerns in some communities, La Jornada newspaper reported.