A warning noted that the victims suffered ear complaints, hearing loss and dizziness.
The State Department has classified these 11 nations as "Do not travel."
A four-level alert system places five Mexican states in the same category as Somalia or Afghanistan.
Archaeologists in their 80s have been coming out of retirement to help with this stunning development.
Mexico tops the list of U.S. tourist deaths caused by homicide in 2016, but Secretary of Tourism Enrique de la Madrid Cordero stresses American travelers are safe.
As North Korea tested a ballistic missile, Tillerson says diplomats and congress members worried about cuts are acting "like the sky was falling."
Senators have called Tillerson's reorganization plan "very unsatisfactory."
Tillerson said violence against the Rohingya Muslim minority showed "characteristics of crimes against humanity."
The U.S. State Department says all registered sex offenders who have molested minors will soon need mandatory marks in their passports identifying them as predators.
Spots became pedestrian crossings and signs designating areas as "parking for embassy cars only" vanished.
Tillerson also wants to remove an envoy for the closure of Guantánamo Bay.
The seven first responders were discovered early Saturday, each of them with gunshot wounds in their heads.