Tens of thousands took part in a mass march down the streets of Mexico City on Wednesday, the latest in a series of protests linked to the disappearance of 43 student-teachers who have been missing since September.

According to the Associated Press, “the largely young crowd carried Mexican flags with black mourning bands replacing the red and green stripes, counting off the numbers from one to 43. Protesters also chanted: ‘They took them away alive, and alive we want them back.'” Many parents of the missing youths, who were allegedly abducted in the city of Iguala on September 26, also joined the demonstration.

Also Wednesday, universities across Mexico began a 72-hour strike to demand justice for the students. TeleSUR reports that the student strike was decided on last week, when the Inter-university Assembly made a decision to paralyze activities at the National Polytechnic Institute, the National Autonomous University of Mexico, the Metropolitan Autonomous University, and the Mexico City Autonomous University.

In addition, religious and civic groups planned to begin a 43-hour hunger strike on Wednesday night.