A magnitude-6.7 earthquake shook eight regions of Chile early Tuesday, causing two people to die of heart attacks, the authorities said.

The victims were Hugo Muñoz Sepúlveda, 72, and Luis Ordenes Tápia, 59, who died in the towns of Quillota and Papudo, both in the Valparaiso region where the temblor hit hardest.

After the quake, whose shock waves extended to the regions of Atacama, 1,000 kilometers (620 miles) north of Santiago, and La Araucania, 700 kilometers (435 miles) south of the capital, the government called on the populace to keep calm.

Deputy Interior Secretary Rodrigo Ubilla said that following the guidelines of the National Emergency Office, or Onemi, the preventive evacuation of the Chilean coast was ordered.

Onemi kept the evacuation order in force for coastal towns in the regions of Coquimbo and Maule until 3:10 a.m. Tuesday, even though the Naval Hydrographic and Oceanography Service, or Shoa, lifted the tsunami alert just 15 minutes after the temblor.

The epicenter of the quake, which struck at 12:50 a.m. Tuesday and lasted approximately one minute, was located at 44 kilometers (27 miles) northwest of the city of Valparaiso and some 170 kilometers (105 miles) northwest of Santiago, with its focus at 31.9 kilometers (20 miles) beneath the earth's surface, according to the Seismological Institute at the University of Chile.

The U.S. Geological Survey, which at first graded the quake as a magnitude-6.4, later raised it to a magnitude-6.7.

Up to 5:00 a.m., the University of Chile registered a number of aftershocks.

According to Onemi, the earthquake affected 68 cities and towns.

Los Libertadores Pass in the Andes, which connects the Chilean city of Los Andes with the city of Mendoza in Argentina remains partially closed due to the poor state of the highway.