Rock singer, Matin 2 Hanjare, Detained By Iranian Officials

Her death led to widespread protests across Iran, which activists have described to ABC News as "the most serious challenge" the government regime has faced in over four decades. Iran Human Rights reported in April that at least 537 people had been killed since the start of the protests and at least 22,000 people have been arrested, according to the Islamic Republic News Agency (IRNA).