"Khamenei's position is surely weakened," Arash Azizi, who unveiled an alleged plot against the supreme leader, told Newsweek.

The fragile ceasefire between Israel and Iran appeared to be holding on Wednesday after a rocky start, giving rise to cautious hope that it could lead to a long-term peace agreement even as Tehran insists it will not give up its nuclear program.

The arrests have raised fears that a new wave of repression is coming, as the government seeks to root out spy networks and clamp down on any dissent.