Sept. 10 (UPI) -- Officials in Mexico revised the death toll from last week's earthquake up to 90 as rescuers continued search efforts Sunday.
At least 71 people died in Oaxaca, the southwest Mexican state's civil protection agency said on Twitter. Mexico's Interior Ministry said 15 died in Chiapas state and four in Tabasco state.
The Mexican Seismological Service recorded 721 aftershocks in the wake of Thursday's 8.1-magnitude temblor. People were camping and sleeping outside out of fear of more aftershocks and damage.
Rescuers were still attempting to find survivors over the weekend, using dogs to help search among debris.
The Pacific Tsunami Warning Center confirmed the quake caused a 5.8-foot tsunami.
Nieto made the declaration after visiting the town of Juchitán, where the quake hit hardest.
Nearly 2 million people were left in the darkness without power following the quake, and schools in 11 states were closed as a safety measure.
Though seismic activity is common in Mexico, officials said Thursday's quake was the strongest to hit the country in 100 years.