The US Geological Service said the two quakes struck south of Ecuador's coastal city of Esmeraldas.
A 6.0-magnitude natural disaster struck off the Pacific nation of Tonga late Sunday, US seismologists said, but no tsunami warning was issued. Authorities said there were no immediate reports of casualties and damage.
A deadly quake killed 663 people in the same area in April.
The first quake registering magnitude 5.9 occurred at 21:01 p.m. (GMT1701) and was located 24.1 kilometers (15 miles) of Muisne, in the province of Esmeralda.
Minutes later at 9.11pm local time, a second stronger quake measuring 6.2 jolted the same area, Xinhua news agency reported citing the institute.
That was Ecuador's worst quake in nearly seven decades, claiming almost 700 lives and leading to approximately 12,000 injuries, with over 24,000 buildings and homes damaged.
Some slight shaking was felt in Ecuador's capital of Quito, which 153 kilomt3ers (94 miles) to the southeast. She wondered if that was because of the Ecuador quake.