A mass grave has been found in the state of Guerrero in Mexico, and it is believed that it may contain the charred remains of some of the more than 40 students missing since clashes with police last week. "A group of investigators and federal public prosecutor specialized agents are on their way to the site. The Mexican state cannot permit such an indignant incident to go unpunished. We want to emphasize that we will put all the forces of the state to shed light on this unfortunate event. Thank you," said Tomas Zeron, Mexican Federal Chief of Investigations. A total of 22 police officers were arrested last week for a confrontation with student protesters.