A bomb went off on a bus in Mexico City on Friday . At least six people were killed , including two minors . Bus drivers say they were afraid of death if they did n't pay extortions . Police are investigating all angles .
A bomb went off on a bus in Guatemala City on Monday . At least six people were killed , including two minors . Bus drivers say they were warned of attacks if they did n't pay extortions . Police are investigating all angles .