A powerful 6.7-magnitude earthquake has hit Ecuador near the Pacific coast area where a devastating quake hit a month ago. President Rafael Correa said on Twitter that the jolt caused only small material damages.

The U.S. Geological Survey said Wednesday that the quake's epicenter was 21 miles from the town of Muisne.

Correa said there was no tsunami alert and called on residents in Quito, where the quake rattled residents in their sleep and led some to evacuate into the streets, to return to their homes.

The much larger magnitude 7.8 earthquake on April 16 killed 660 and initially left tens of thousands homeless. It has been followed by hundreds of aftershocks, some as strong as 6.6 on the Richter scale.

Ecuador was already struggling economically before the April disaster. Correa has hiked taxes to fund the recovery but says it will take years to rebuild the beach towns and tourist hubs leveled by the quake.