At least five people have died -- two from cardiac arrest. Another three were crushed by falling debris.
"A quake of this magnitude has the potential to generate a destructive tsunami that can beat the coastline around the epicenter within minutes and more distant coastlines in a matter of hours," the PTCW said.
Though officials have reported landslides and power outages, the extent of the damage is still unclear.
The earthquake triggered a tsunami warning for three nearby countries, Chile, Peru and Ecuador, and tsunami watches for Colombia, Panama, Costa Rica and Nicaragua. Tsunami warnings are still in effect for Chile and Peru.
BREAKING: Tsunami warning triggered for Chile, Peru, and Ecuador.Colombia, Panama, Costa Rica are under watch, following the 8.0 quake.— UPI.com (@UPI) April 2, 2014
Chilean authorities ordered the evacuation of coastal communities.
This video (via Buzzfeed) appears to show the loudspeaker warnings in Antofagasta, Chile.
Iquique is a port city near some of the country's largest copper mines. It has a population of 180,000.
This earthquake follows a 6.7-magnitude quake that hit off the Iquique coast on March 16.
[ABC News, CNN]