MEXICO CITY-- A major earthquake off Mexico's southern coast killed at least five people, with the president saying Friday it was the biggest in a century to hit the country. Houses toppled and the quake produced tsunami waves and sent people running into the streets in panic. 

The U.S. Geological Survey reported the earthquake's magnitude as 8.1, but President Enrique Pena Nieto said it was 8.2, making it the largest in Mexico in 100 years. He also said it was bigger than the one in 1985, when thousands were killed in four Mexican states. 

"It was a large-scale earthquake," Pena Nieto said. "It had a bigger magnitude than the one Mexicans knew in 1985."

He said that 62 aftershocks followed the quake and it was possible one as strong as 7.2 could hit in the next 24 hours. Pena Nieto also said that serious damage had been caused and that 1 million customers initially had been without power following the quake, but that electricity had been restored to 800,000 of them. 

The Pacific Tsunami Warning Center said waves of 3.3 feet above the tide level were measured off Salina Cruz. Smaller tsunami waves were observed on the coast or measured by ocean gauges in several other places. 

The center's forecast said Ecuador, El Salvador and Guatemala could see waves of a meter or less. No threat was posed to Hawaii and the western and South Pacific. 

The quake was so strong that it caused buildings to sway violently in Mexico's capital, more than 650 miles away. Residents fled buildings, many in their pajamas, and gathered in frightened groups in the street. Some neighborhoods remained in darkness after electricity was knocked out.

CBS Dallas' Jeff Paul was in Puerto Escondido when the quake hit, and said he saw his house sway, and the motion of the earth cause waves in a nearby swimming pool.

"It was one of those experiences where it kind of left you shaking there for a while," he said.

The U.S. Geological Survey said the quake struck at 11:49 p.m. Thursday local time, with an epicenter 102 miles west of Tapachula in Chiapas, not far from Guatemala. It was approximately 43 miles deep.

The USGS reported several aftershocks, all greater than a 5 magnitude, the Reuters news agency reported. 

Mexico's civil protection agency said it was the strongest quake to hit the capital since a devastating 1985 temblor flattened swathes of Mexico City and killed thousands, Reuters reports.