Mexico city, Mexico. 6th November, 2014. An art work displaying the face of a missing student is displayed in Reforma Avenue in Mexico City during a protest demanding justice for the disappearance of 43 students from Ayotzinapa school in the state of Guerrero. 43 teachers college students disappeared over a month ago, when investigators say police detained the students and handed them over to a drug gang.Picture taken November 6, 2014. Credit: Chico Sanchez/Alamy Live News

- Image ID: EA4T1W
Mexico city, Mexico. 6th November, 2014. An art work displaying the face of a missing student is displayed in Reforma Avenue in Mexico City during a protest demanding justice for the disappearance of 43 students from Ayotzinapa school in the state of Guerrero. 43 teachers college students disappeared over a month ago, when investigators say police detained the students and handed them over to a drug gang.Picture taken November 6, 2014. Credit: Chico Sanchez/Alamy Live News
Chico Sanchez / Alamy Stock Photo
Image ID: EA4T1W
Mexico city, Mexico. 6th November, 2014. An art work displaying the face of a missing student is displayed in Reforma Avenue in Mexico City during a protest demanding justice for the disappearance of 43 students from Ayotzinapa school in the state of Guerrero. 43 teachers college students disappeared over a month ago, when investigators say police detained the students and handed them over to a drug gang.Picture taken November 6, 2014. © Chico Sanchez/Alamy Live News
Location: Avenida Paseo de la Reforma, Mexico City, Mexico