Santiago - A powerful earthquake measuring 7.8 rocked northern Chile late on Wednesday, just a day after a deadly 8.2 jolt in the same region, authorities said.
Sirens rang as a tsunami warning was issued and thousands of people in the north who had just endured the latest quake were again ordered to evacuate inland from coastal areas, according to authorities.
Peru to the north also declared another tsunami warning, according to its Navy.
The new temblor struck at 23:43 (0143 GMT Thursday), 20km south of the city of Iquique, the navy's alert service said.
"Based on its strength a tsunami warning has been issued," the Chilean national oceanographic agency, known as SHOA, added.
There were no immediate reports of fatalities or major damage from the new quake.
Waves have started lashing the coast, said Ricardo Toro of the national disaster relief agency Onemi.
Chilean President Michelle Bachelet, who was assessing damage in the northern city of Arica far north of the capital Santiago, was among those evacuated to higher ground, said state run TVN.
Thousands of Chileans had just returned home after spending the night on hills following Tuesday's 8.2-magnitude earthquake that killed six people and sparked tsunami fears as far as Japan.
The tremors on Tuesday were felt as far inland as landlocked Bolivia and sparked evacuation warnings up the Pacific coast of South America and into Central America.