Two strong aftershocks killed one person and injured 85 Wednesday as they shook Ecuador a month after a devastating earthquake left some 700 dead, President Rafael Correa said.

Terrified Ecuadorans poured into the streets after waking up in the middle of the night to a 6.8-magnitude earthquake, which hit as the country is struggling to clean up the devastation left by a powerful 7.8-magnitude quake on April 16.

The pre-dawn quake, which struck Ecuador's northwestern coast, was followed by another 6.7-magnitude quake in approximately the same region just before noon.

A man died in the town of Tosagua and 85 people sustained light injuries, Correa told a news conference.

The cause of the man's death was "somewhat unclear," he said.

"He ran out into the street fleeing the earthquake, fell and hit the base of his skull. But according to another version, a beam fell on him. So we are trying to clarify," Correa said.

Ecuador is still reeling from the April earthquake, which flattened homes and buildings up and down a long stretch of Pacific coast, reduced picturesque resort towns to rubble and left hundreds of people buried in the ruins.

The government estimates the cost of the quake at $3 billion. Some 29,000 people left homeless are still living in shelters.

The two new quakes struck near the resort town of Mompiche, 60 kilometers (37 miles) north of Pedernales, the town hardest hit by last month's quake.

The pre-dawn quake, which struck at 2:57 am (0757 GMT), had a depth of 32 kilometers. Its epicenter was in the western province of Manabi, 136 kilometers northwest of Quito, the US Geological Survey said.

The second quake struck at 11:47 am (1647 GMT) in Esmeraldas province on the Colombian border, Ecuador's Geophysical Institute said.

- 'Nature is testing us' -

Correa took to Twitter to calm a jittery nation.

"The aftershock is similar to the one at dawn," the president wrote after the second quake. "NO tsunami alert."

Earlier, he told Ecuadorans that "nature is testing us," warning that "there will be more aftershocks" of magnitude 6 or more.

Both earthquakes were felt as far away as the Colombian city of Cali, 480 kilometers to the northeast. No injuries or damage were reported there, Colombian President Juan Manuel Santos said.

In Ecuador's capital Quito, where the quake was also felt, homes and government buildings emptied.

Fearful of more aftershocks, many residents lingered in the street or parks.

"I was at the office," government worker Mariela Diaz said. "It's a four-floor building. I just put my faith in God, nothing more."

Parents had been called to pick up their children from school as part of the country's earthquake security plan, Correa said.

Classes were cancelled in Esmeraldas and Manabi provinces until Monday to give the authorities time to inspect school and university buildings for structural damage.

The government, criticized last year for imposing "prior censorship" on the news media in the wake of a volcanic eruption, also banned protests and other mass gatherings in the two provinces indefinitely.