Congo opposition candidate Martin Fayulu rejected a court ruling on Sunday that his rival won a presidential election, declaring himself president in a move that could stoke further unrest.

“The constitutional court has just confirmed that it serves a dictatorial regime by validating false results, (and enabling) a constitutional coup d’etat,” he said in a statement.

The court confirmed Felix Tshisekedi’s presidential election win on Sunday, throwing out two challenges against it.